SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549



                                    FORM 8-K


                                 CURRENT REPORT
                     PURSUANT TO SECTION 13 or 15(d) of the
                         SECURITIES EXCHANGE ACT OF 1934


         Date of report (Date of earliest event reported) June 28, 1999

             Exact name of registrant as specified in its
             charter, State or other jurisdiction of
             incorporation or organization, Address of
Commission   principal executive offices and Registrant's        IRS Employer
File Number  Telephone Number,including area code             Identification No.
-----------  ------------------------------------             ------------------

1-12927    NEW CENTURY ENERGIES, INC.                            84-1334327
           (a Delaware Corporation)
           1225 17th Street
           Denver, Colorado  80202
           Telephone (303) 571-7511

1-3280     PUBLIC SERVICE COMPANY OF COLORADO                    84-0296600
           (a Colorado Corporation)
           1225 17th Street
           Denver, Colorado  80202
           Telephone (303) 571-7511

1-3789     SOUTHWESTERN PUBLIC SERVICE COMPANY                   75-0575400
           (a New Mexico Corporation)
           Tyler at Sixth
           Amarillo, Texas  79101
           Telephone (303) 571-7511






<PAGE>




This combined Form 8-K is separately filed by New Century Energies Inc.,  Public
Service Company of Colorado and Southwestern Public Service Company. Information
contained herein relating to any individual  company is filed by such company on
its own behalf.  Each  registrant  makes  representations  only as to itself and
makes no other  representations  whatsoever  as to  information  relating to the
other registrants.

Item 5.  OTHER EVENTS

At special  shareholder  meetings on June 28, 1999,  the  shareholders  of New
Century  Energies,  Inc.  and  Northern  States  Power  Company  approved  the
Agreement and Plan of Merger, dated March 24, 1999.

Additional  information  regarding  this  merger to form Xcel  Energy  Inc. is
provided  in the  press  release  filed  as  Exhibit  99 in Item 7.  FINANCIAL
STATEMENTS AND EXHIBITS.

Item 7.  FINANCIAL STATEMENTS AND EXHIBITS

      Exhibit 99  Press release dated June 28, 1999


<PAGE>
                                                                      EXHIBIT 99

                               JOINT NEWS RELEASE

   For NCE:                                     For NSP:
   Media Relations:                                   Media Relations
   (303) 294-8900                               (612) 337-2167
   Investors:                                         Investors
   Mike Pritchard                               Richard Kolkmann
   (303) 294-2588                               (612) 330-6622
   www.ncenergies.com                           www.nspco.com

                                                NCE & NSP shareholders approve
                                               merger to form Xcel Energy Inc.

      DENVER and MINNEAPOLIS (June 28, 1999) - Shareholders of New Century
Energies (NYSE: NCE) and Northern States Power Co. (NYSE: NSP) Monday
approved the merger of NCE and NSP to form Xcel Energy Inc.

      At  separate  special  shareholder  meetings  held  today  in  Denver  and
Minneapolis, more than 83 percent of the voting shares of both NCE and NSP voted
in favor of the merger.

      Jim Howard, president,  chairman and chief executive officer of NSP, said,
"Today our shareholders  voted to merge two strong,  complementary  companies to
create  Xcel  Energy,  which  will be  well-positioned  to  compete in a rapidly
changing  utility  industry."  Howard will become chairman of Xcel Energy at the
completion of the merger.

      NCE  Chairman  Bill  Helton  said,  "This  vote  of  confidence  from  the
shareholders  of both  companies is an important  step forward as we continue to
make excellent progress in completing our merger in a timely manner."

      NCE and NSP shareholders  recognize substantial benefits of the merger for
shareholders and consumers alike, according to NCE President Wayne Brunetti, who
will become chief executive  officer of Xcel Energy.  "This  transaction will be
accretive  immediately,  will provide a balanced  platform for growth,  and will
provide NCE and NSP customers  with  continued  low-cost,  reliable  energy," he
said.

                                   -- more --


<PAGE>


                                NSP/NCE News Release - 28 June 1999 - Page Two

      NCE announced that  shareholder  approval of the merger totaled 93 percent
of votes received, and 78 percent of overall shares. NSP reported 83 percent and
62 percent, respectively.

      The merger,  announced on March 25, 1999,  requires approval or regulatory
review by federal regulators, including the Federal Energy Regulatory Commission
and the Securities and Exchange Commission, as well as state regulators in eight
of the 12 states served by the two companies.  The approval  process is expected
to be completed within 12 to 18 months from the date of the merger announcement.

      Under terms of the merger agreement, upon completion, holders of NCE stock
will  receive  1.55  shares of stock in Xcel Energy for each share of NCE stock.
Each share of NSP stock will become one share of Xcel  Energy.  When  completed,
Xcel Energy will serve 3 million  electricity  customers and  approximately  1.5
million natural gas customers in 12 states.

      NCE serves approximately 1.6 million electricity customers and more
than a million natural gas customers in Colorado, Texas, New Mexico, Wyoming,
Kansas and Oklahoma.  Its operating companies include Public Service Co. of
Colorado, Southwestern Public Service Co. and Cheyenne Light, Fuel & Power.
Wholly owned subsidiaries include New Century International, which owns a 50
percent interest in Yorkshire Electricity in the United Kingdom.

      NSP  provides  electricity  to about 1.5 million  customers in portions of
Minnesota,  Wisconsin,  North Dakota,  Michigan and South Dakota. It distributes
natural  gas to more than  475,000  customers  in  Minnesota,  Wisconsin,  North
Dakota,  South Dakota,  Michigan and Arizona.  Wholly owned subsidiaries include
NRG Energy Inc.,  which  operates and has ownership  interests in  non-regulated
energy  businesses  around the world,  with major projects in the United States,
Australia and Germany.

   This news release includes forward-looking statements within the meaning of
    Section 21E of the Securities Exchange Act of 1934. These forward-looking
   statements reflect numerous assumptions, and involve a number of risks and
   uncertainties. Among the factors that could cause actual results to differ
       materially are: electric load and customer growth, abnormal weather
     conditions, economic conditions in the companies' service territories,
    fluctuations in energy-related commodity prices, realization of net cost
   savings in a timely manner, and other uncertainties. Other risk factors are
            detailed from time to time in the companies' SEC reports.

                                       ###



<PAGE>



                                   SIGNATURES


Pursuant  to the  requirements  of the  Securities  Exchange  Act of 1934,  each
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned, thereunto duly authorized.



                                         NEW CENTURY ENERGIES, INC.


                                             /s/Richard C. Kelly
                                          -----------------------------
                                              Richard C. Kelly
                                          Executive Vice President and
                                           Chief Financial Officer



                                    PUBLIC SERVICE COMPANY OF COLORADO


                                             /s/Brian P. Jackson
                                          -----------------------------
                                              Brian P. Jackson
                                          Senior Vice President, Finance and
                                          Administrative Services,
                                          Chief Financial Officer and Treasurer



                                    SOUTHWESTERN PUBLIC SERVICE COMPANY


                                             /s/Brian P. Jackson
                                          -----------------------------
                                              Brian P. Jackson
                                          Senior Vice President, Finance and
                                          Administrative Services,
                                          Chief Financial Officer and Treasurer



Dated:   June 28, 1999
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SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT
                     PURSUANT TO SECTION 13 or 15(d) of the
                         SECURITIES EXCHANGE ACT OF 1934

         Date of report (Date of earliest event reported) June 28, 1999

             Exact name of registrant as specified in its
             charter, State or other jurisdiction of
             incorporation or organization, Address of
Commission   principal executive offices and Registrant's        IRS Employer
File Number  Telephone Number,including area code             Identification No.
-----------  ------------------------------------             ------------------

1-12927    NEW CENTURY ENERGIES, INC.                            84-1334327
           (a Delaware Corporation)
           1225 17th Street
           Denver, Colorado  80202
           Telephone (303) 571-7511

1-3280     PUBLIC SERVICE COMPANY OF COLORADO                    84-0296600
           (a Colorado Corporation)
           1225 17th Street
           Denver, Colorado  80202
           Telephone (303) 571-7511

1-3789     SOUTHWESTERN PUBLIC SERVICE COMPANY                   75-0575400
           (a New Mexico Corporation)
           Tyler at Sixth
           Amarillo, Texas  79101
           Telephone (303) 571-7511
This combined Form 8-K is separately filed by New Century Energies Inc.,  Public
Service Company of Colorado and Southwestern Public Service Company. Information
contained herein relating to any individual  company is filed by such company on
its own behalf.  Each  registrant  makes  representations  only as to itself and
makes no other  representations  whatsoever  as to  information  relating to the
other registrants.

Item 5.  OTHER EVENTS

At special  shareholder  meetings on June 28, 1999,  the  shareholders  of New
Century  Energies,  Inc.  and  Northern  States  Power  Company  approved  the
Agreement and Plan of Merger, dated March 24, 1999.

Additional  information  regarding  this  merger to form Xcel  Energy  Inc. is
provided  in the  press  release  filed  as  Exhibit  99 in Item 7.  FINANCIAL
STATEMENTS AND EXHIBITS.

Item 7.  FINANCIAL STATEMENTS AND EXHIBITS

      Exhibit 99  Press release dated June 28, 1999
EXHIBIT 99

                               JOINT NEWS RELEASE

   For NCE:                                     For NSP:
   Media Relations:                                   Media Relations
   (303) 294-8900                               (612) 337-2167
   Investors:                                         Investors
   Mike Pritchard                               Richard Kolkmann
   (303) 294-2588                               (612) 330-6622
   www.ncenergies.com                           www.nspco.com

                                                NCE & NSP shareholders approve
                                               merger to form Xcel Energy Inc.

      DENVER and MINNEAPOLIS (June 28, 1999) - Shareholders of New Century
Energies (NYSE: NCE) and Northern States Power Co. (NYSE: NSP) Monday
approved the merger of NCE and NSP to form Xcel Energy Inc.

      At  separate  special  shareholder  meetings  held  today  in  Denver  and
Minneapolis, more than 83 percent of the voting shares of both NCE and NSP voted
in favor of the merger.

      Jim Howard, president,  chairman and chief executive officer of NSP, said,
"Today our shareholders  voted to merge two strong,  complementary  companies to
create  Xcel  Energy,  which  will be  well-positioned  to  compete in a rapidly
changing  utility  industry."  Howard will become chairman of Xcel Energy at the
completion of the merger.

      NCE  Chairman  Bill  Helton  said,  "This  vote  of  confidence  from  the
shareholders  of both  companies is an important  step forward as we continue to
make excellent progress in completing our merger in a timely manner."

      NCE and NSP shareholders  recognize substantial benefits of the merger for
shareholders and consumers alike, according to NCE President Wayne Brunetti, who
will become chief executive  officer of Xcel Energy.  "This  transaction will be
accretive  immediately,  will provide a balanced  platform for growth,  and will
provide NCE and NSP customers  with  continued  low-cost,  reliable  energy," he
said.

                                   -- more --
NSP/NCE News Release - 28 June 1999 - Page Two

      NCE announced that  shareholder  approval of the merger totaled 93 percent
of votes received, and 78 percent of overall shares. NSP reported 83 percent and
62 percent, respectively.

      The merger,  announced on March 25, 1999,  requires approval or regulatory
review by federal regulators, including the Federal Energy Regulatory Commission
and the Securities and Exchange Commission, as well as state regulators in eight
of the 12 states served by the two companies.  The approval  process is expected
to be completed within 12 to 18 months from the date of the merger announcement.

      Under terms of the merger agreement, upon completion, holders of NCE stock
will  receive  1.55  shares of stock in Xcel Energy for each share of NCE stock.
Each share of NSP stock will become one share of Xcel  Energy.  When  completed,
Xcel Energy will serve 3 million  electricity  customers and  approximately  1.5
million natural gas customers in 12 states.

      NCE serves approximately 1.6 million electricity customers and more
than a million natural gas customers in Colorado, Texas, New Mexico, Wyoming,
Kansas and Oklahoma.  Its operating companies include Public Service Co. of
Colorado, Southwestern Public Service Co. and Cheyenne Light, Fuel & Power.
Wholly owned subsidiaries include New Century International, which owns a 50
percent interest in Yorkshire Electricity in the United Kingdom.

      NSP  provides  electricity  to about 1.5 million  customers in portions of
Minnesota,  Wisconsin,  North Dakota,  Michigan and South Dakota. It distributes
natural  gas to more than  475,000  customers  in  Minnesota,  Wisconsin,  North
Dakota,  South Dakota,  Michigan and Arizona.  Wholly owned subsidiaries include
NRG Energy Inc.,  which  operates and has ownership  interests in  non-regulated
energy  businesses  around the world,  with major projects in the United States,
Australia and Germany.

   This news release includes forward-looking statements within the meaning of
    Section 21E of the Securities Exchange Act of 1934. These forward-looking
   statements reflect numerous assumptions, and involve a number of risks and
   uncertainties. Among the factors that could cause actual results to differ
       materially are: electric load and customer growth, abnormal weather
     conditions, economic conditions in the companies' service territories,
    fluctuations in energy-related commodity prices, realization of net cost
   savings in a timely manner, and other uncertainties. Other risk factors are
            detailed from time to time in the companies' SEC reports.

                                       ###
SIGNATURES

Pursuant  to the  requirements  of the  Securities  Exchange  Act of 1934,  each
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned, thereunto duly authorized.

                                         NEW CENTURY ENERGIES, INC.

                                             /s/Richard C. Kelly
                                          -----------------------------
                                              Richard C. Kelly
                                          Executive Vice President and
                                           Chief Financial Officer

                                    PUBLIC SERVICE COMPANY OF COLORADO

                                             /s/Brian P. Jackson
                                          -----------------------------
                                              Brian P. Jackson
                                          Senior Vice President, Finance and
                                          Administrative Services,
                                          Chief Financial Officer and Treasurer

                                    SOUTHWESTERN PUBLIC SERVICE COMPANY

                                             /s/Brian P. Jackson
                                          -----------------------------
                                              Brian P. Jackson
                                          Senior Vice President, Finance and
                                          Administrative Services,
                                          Chief Financial Officer and Treasurer

Dated:   June 28, 1999