EXHIBIT 99.4



[NSTAR LOGO APPEARS HERE]                         NEWS RELEASE

CONTACTS:
MEDIA:                                            INVESTORS:
Name: Michael Monahan                             Name: Philip J. Lembo
Phone: (617) 424-2460                             Phone: (617) 424-3562

For Immediate Release

           BEC ENERGY AND COMMONWEALTH ENERGY SYSTEM COMPLETE MERGER


Boston, MA (August 25, 1999)  BEC Energy (NYSE: BSE) and Commonwealth Energy
System (NYSE: CES), today completed their merger under a new company, NSTAR
(NYSE: NST).  This follows approval from the Securities and Exchange Commission
yesterday.  The merger, completed in less than nine months, provides the
platform for creating the premier energy distribution system in the region.

NSTAR, through its subsidiaries, Boston Edison, Cambridge Electric, Commonwealth
Electric and Commonwealth Gas, will serve about 1.3 million customers, including
approximately 1,040,000 electric customers in 81 communities and 240,000 gas
customers in 51 communities.

Thomas J. May, chairman and chief executive officer of NSTAR, said, "Customer
service is our top priority.  Our expanded platform will allow the combined
companies to invest more effectively in technology and infrastructure which will
lead to higher levels of customer service." Mr. May added, "The new company
allows us to broaden our customer base, and to capture the savings opportunities
that the combined operations can produce."

May also noted that the electric and gas utility industry, particularly in the
northeast region, continues to experience significant consolidation activity.
"Like all utilities in the region, we will continue to evaluate opportunities to
enhance shareholder value through the consolidation of this industry,"  May
said.

Under the terms of the Agreement and Plan of Merger (the "Merger Agreement"),
the BEC Energy shareholders have the right to elect to receive either $44.10 in
cash or one NSTAR common share for each BEC Energy share held, and the
COM/Energy shareholders have the right to elect to receive either $44.10 in cash
or 1.05 NSTAR common shares for each COM/Energy share held, subject in each case
to proration as described in the Proxy Statement/Prospectus dated May 14, 1999
relating to the merger.

                                    - more -

                                      -1-


Election forms were mailed to the BEC Energy and COM/Energy shareholders
beginning on August 24, 1999.  The cash or share election must be completed and
returned to EquiServe, the exchange agent, no later than 5:00 p.m. ("EST") on
September 21, 1999.  Any shareholder who fails to make a timely election will
receive either cash or NSTAR common shares at the discretion of NSTAR.

In April 1998, BEC announced a common share repurchase program under which it
would repurchase up to four million of its common shares.  This share repurchase
program will be continued by NSTAR.

As previously announced, on July 29, 1999, a wholly-owned special purpose
subsidiary of Boston Edison Company, a subsidiary of NSTAR, closed the sale of
$725 million of rate reduction bonds through two Massachusetts state agencies
and expects to use a portion of the proceeds to reduce capitalization.  On July
30, 1999 Boston Edison announced a tender offer for any and all of its
outstanding 9-7/8% debentures due June 1, 2020 and its 9-3/8% debentures due
August 15, 2021.  In addition, NSTAR may expand its existing common share
repurchase program.  Repurchases of NSTAR common shares could take the form of
an open-market repurchase program, private transactions, one or more tender
offers or a combination of one or more of these methods.  In the event that
NSTAR elects to proceed with a tender offer, any such tender offer would likely
be at a premium to the then current market price of NSTAR shares.

On July 27, 1999, the Massachusetts Department of Telecommunications and Energy
(the "MDTE"), approved a rate plan filed by the utility subsidiaries of NSTAR in
connection with the merger. On August 16, 1999, the Massachusetts Attorney
General, and other parties to the rate proceeding, filed an appeal of the MDTE's
order regarding the rate plan.

This press 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: the ability of the combined company to successfully reduce its
cost structure and realize the economies expected to be generated by the merger,
including benefits from consolidation of the companies' workforces, the effects
of the continued regulatory orders and legislative changes; the effects of the
changes in economic conditions, weather conditions, growth in the service
territories of the two companies, interest costs and the other risks detailed
from time to time in BEC Energy's, Commonwealth Energy System's, and NSTAR's SEC
reports.  See the Annual Reports of each of BEC Energy and Commonwealth Energy
System for the years ended December 31, 1998.

                                    - end -

                                      -2-