In expectation of a regulation prohibiting under-age drinking at Harvard, several Masters' open houses yesterday were free of the normally abundant alcohol.

Masters anticipated what is expected to be a dramatic reversal in the University's alcohol policy, likely to prohibit any student under 21 years old from drinking at an open party or function.

The new policy, which officials said would be modeled after Yale's strict guidelines, will replace the current system under which Harvard serves "in loco parentis" for most alcohol-related activities. The old policy banned drinking for under-age students only in publicized, University-wide events such as football games.

North House co-Master Hanna M. Hastings served soft-drinks, cider and a punch made from fresh-grown grapes at her open house yesterday afternoon. There was no beer or wine as in the past, she said.

Hastings said she regretted the change because students did not drink in excess at the House, and there were no problems related to alcohol. "But it is the law and Harvard really can't be above the law," she said.

Leverett House co-Master Judy Dowling said although the House usually serves beer and sherry, "We just aren't going to serve alcohol anymore at our open houses."

Rick O'Rourke '87, a Leverett House resident, was unhappy with the change. "At an open house, you turn the lights up and the music down. It's not a party that is likely to get out of control. It's highly supervised," he said.

Winthrop's open house was also dry, prompting several residents to go to the Hong Kong, according to one student.

Dunster House did not have an open house yesterday, but Master Sally Moore said next week's would be alcohol free.

"We don't feel we can break the law," Moore said.

But some houses, including Mather and Cabot, continued to provide alcoholic beverages, despite the expected policy change.

"We've been having open houses of this kind for 10 years and we've never had any difficulties. But the law is the law and unless there is some interpretation that would allow us to continue into the future, we shall have to change," said Mather House Master David J. Herlihy.