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[NSTAR LOGO] NSTAR

                                                                    NEWS RELEASE


Contact: Philip J. Lembo
Phone:   (617)424-3562
e-mail:  ir@nstaronline.com

For Immediate Release                                           January 27, 2000

                         NSTAR ANNOUNCES 1999 EARNINGS

Boston, MA -- Nstar (NST - NYSE) today reported earnings of $0.35 per basic and
diluted share, respectively, for the three months ended December 31, 1999 versus
$0.15, for the same period in 1998. For the year ended December 31, 1999,
earnings per basic and diluted share were $2.77 and $2.76, respectively,
compared to $2.76 and $2.75 in 1998. The fourth quarter of 1999 represents the
first full quarter of NSTAR, following the merger of BEC Energy and Commonwealth
Energy System in August.

Chairman and Chief Executive Officer Tom May said, "The company was again
successful in shaping and solidifying its future. NSTAR was a top performer in
the industry in terms of stock value and total shareholder return. At the same
time we accomplished critical strategic and operating objectives, and improved
service to customers."

May added that NSTAR is fully committed to enhancing shareholder value. In July,
the company was the first in the nation to close on the sale of a nuclear power
plant. In August, the company nearly doubled its customer base by completing its
merger with COM/Energy in record time for the industry. Later in the year NSTAR
announced a $300 million common share buyback program and increased its dividend
by 3.1%.

May added that the company's telecommunications joint venture with RCN
Corporation will help create additional shareholder value in today's booming
telecommunications market.

The results for the year and the quarter reflect the positive contribution of
the former COM/Energy subsidiaries for the last four months of 1999. The
comparison of 1999 to 1998 is impacted by NSTAR's Boston Edison subsidiary,
which experienced a 4.7% increase in retail electric sales for the year and
significant cost reductions as a result of operating efficiencies and generating
unit divestitures and lower financing costs. However, the impact of the retail
electric rate reduction mandated by the Massachusetts Electric Utility
Restructuring Law, the amortization of goodwill and
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merger related costs, and the higher level of common shares outstanding as a
result of the merger partially offset these positive impacts. Prior year
results reflect only the results of BEC Energy.

In addition, earnings per share for the year is impacted by one-time costs
associated with an $11.3 million ($0.14 per share) reduction in the carrying
value of non-regulated district energy assets.

NSTAR was formed in August 1999 through a merger of BEC Energy and Commonwealth
Energy System. The company, headquartered in Boston, MA, provides regulated
electric and gas utility services and is also engaged in telecommunications and
other non-regulated activities. NSTAR, through its subsidiaries, Boston Edison
Company, Cambridge Electric Light Company, Commonwealth Electric Company and
Commonwealth Gas Company, serves approximately 1.3 million customers
throughout Massachusetts, including approximately 1,040,000 electric customers
in 81 communities and 240,000 gas customers in 51 communities. More information
can be found at the company's Web site - WWW.NSTARONLINE.COM.

FINANCIAL DATA (in thousands except per share data)





3 months ended December 31:              1999          1998         % Change
- -----------------------------------------------------------------------------
                                                             
Operating revenues                     $  582,787    $  363,153        60.5%
Net income                             $   22,353    $    8,374       166.9%
Preferred dividends provided           $    1,490    $    1,490         0.0%
Earning per share
                  - basic              $     0.35    $     0.15       133.3%
                  - diluted            $     0.35    $     0.15       133.3%
Weighted avg. # of shares
                  - basic                  59,653        47,184        26.4%
                  - diluted                59,793        47,366        26.2%
Dividend declared per share
  of common stock                      $     0.50    $    0.485         3.1%



12 months ended December 31:              1999          1998         % Change
- -----------------------------------------------------------------------------
                                                             
Operating revenues                     $1,851,098    $1,622,515        14.1%
Net income                             $  146,427    $  141,046         3.8%
Preferred dividends provided           $    5,960    $    8,765       (32.0%)
Earning per share
                  - basic              $     2.77    $     2.76         0.4%
                  - diluted            $     2.76    $     2.75         0.4%
Weighted avg. # of shares
                  - basic                  50,796        47,973         5.9%
                  - diluted                50,921        48,149         5.8%
Dividend declared per share
  of common stock                      $    1.955    $    1.895         3.2%





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