BOSTON--By the narrowest of margins, Massachusetts citizens seemed to have voted yesterday to abolish rent control, a fixture of--Cambridge life for a quarter-century.

With 55 percent of precincts reporting, Question 9--the ballot question that promises to bring rent control to an end--had received 52 percent of the vote. Forty-eight percent voted against the measure.

The referendum, which carries the force of law, will affect Cambridge, Boston and Brookline, the three communities in Massachusetts with rent control. It will allow landlords to raise rents at will.

After January 1, communities will only be permitted to adopt rent control for six months, and only for units whose rents are $400 or less and whose owners possess 10 or more units. After six months, landlords cannot be forced to continue rent control.

In Cambridge, 14,415 rent-controlled apartments, more than a third of all units in the city, are likely to go on the open market. While Harvard has remained neutral on Question 9, Harvard Real Estate, the University-affiliated owner of 709 of those units and the largest landlord in the city, stands to gain considerably from the rent increases.

The vote signals an important victory by the Massachusetts Home-owners Coalition (MHC), which conducted a no-holds-barred campaign in placing the question on the ballot, fighting a constitutional challenge in State Judicial Court over the summer and spending more than $650,000 in an expensive media blitz for the proposition.

But pro-rent control activists, led by the six-month-old Save Our Communities Coalition (SOCC), vowed Slast night to bring the issue to the Massachusetts legislature and the courts. The state could conceivably reinstate the program.

MHC activists celebrated their victory late last night at the Veterans of Foreign Wars post in Cambridge. Landlords believe that rent control makes property repairs unaffordable, and have railed against the complex regulations of city rent control boards. They charge rent control is abused by citizens who can afford market rents.

Cambridge Mayor Kenneth E. Reeves '72 lives in a rent-controlled apartment, as does Supreme Judicial Court Justice Ruth Abrams.

Denise A. Jillson, chair of MHC, last night reiterated landlords' claims that they are unfairly forced to subsidize tenants at sub-market rates.

"Is it fair to force one small segment of the population to subsidize [tenants]?" she asked. "Is it fair that small property owners be prevented from living on their own property?"

Rent control supporters, about 160 of whom gathered at SOCC's downtown Boston headquarters, repeated their assertions that Question 9 will displace elderly and low- and moderate-income tenants. "This will be absolutely devastating." Michael H. Turk, co-chair of the Cambridge Tenants Union, said last night. "It will end up turning Cambridge into an upper-income suburban enclave."

Question 9 opponents said the referendum violates the autonomy of local communities. "It's up to voters in those communities to decide on the bill," said Benjamin N. Nidus, a Cambridge rent-control tenant who voted yesterday at Gund Hall.

'I'd move,' one tenant says of the proposition's effects.

For a generation, rent control has been the most politically divisive issue in Cambridge. While the city council voted 8-1 last month to oppose Question 9, the lone dissenter, Councillor William H. Walsh, repeated his assertions last night that the program is unfair to landowners.

Walsh said he supports measures to moderate rent control's effects, including subsidies for elderly tenants. But he has repeatedly refused to go along with anything short of abolition.