Gov. William F. Weld '66 signed an emergency act Wednesday that would grant a two-year reprieve of rent control's abolition for certain income-eligible tenants, but the act's limited protection for rent-control tenants have Cambridge landlords, tenants and officials in shock.

Weld's approval of the bill, which both houses of the state legislature passed in the final minutes of the legislative year on Tuesday, seals the fate of rent control in Cambridge, Boston and Brookline, the three communities in Massachusetts with rent control laws.

Under the act--which the three communities cannot alter or reject--tenants earning less than 60 percent of the median-income guidelines for metropolitan Boston, as set up by the federal Department of Housing and Urban Development (HUD), can keep rent control for up to two years. Also protected are elderly and disabled tenants who make less than 80 percent of the HUD guidelines.

The Rev. Vernon E. Carter, who lives in a rent-controlled apartment in Cambridge, says he'll be able to keep his unit because of his advanced age. But he worries about the impact of the rent control's loss on students and other renters.

No full-time students older the age of 18 can qualify for rent control.

"The realtors are exploiting students," Carter says. "I'm a senior citizen so I fall under the protection. The students should raise protests in order to protect their rights."

The protections are far weaker than the petition Cambridge had originally asked the state legislature to grant. That home-rule petition had called for a five-year phase-out of rent control for elderly, disabled and low-and moderate-income tenants.

By January 1, 1997, rent control will by completely abolished the state of Massachusetts.

'All Controls Expire'

Until yesterday, rent control regulated more than 16,000 housing units in Cambridge, which enacted rent control laws in 1970.

Terrence P. Morris, executive director of the Cambridge Rent Control Board, estimated that only 6000 to 8000 units fall under the new exemptions.

By law, landlords were legally empowered to mail rent-increase notices starting yesterday. The soonest the increase can legally take effect is March 1, according to Morris. "Landlords are free to give notices of rent increases, effective March 1, for everybody," the director said.

The rent-control board met for three hours yesterday, hastening to respond to a flurry of calls from anxious tenants.

The board decided yesterday to send a mass mailing to around 23,000 tenants and landlords, clarifying the new laws. The board will certify tenants who meet the income guidelines.

"They can come in and we request documentation to verify they are under the income guidelines," Morris said. "We will issue them a certificate to that effect."

"We expect to see them come in en masse," Morris added.