Twenty-five employees of two Cambridge restaurants were locked our of their jobs yesterday after they picked the entries to protest management's position in ongoing contract negotiations.

But after a negotiating session last night, a representative of the workers predicted a settlement this morning, although pickets will be standing by if talks become stalled again.

The waiters, waitresses, and bartenders at Ferdinand's and the Ha' Penny Pub, which are owned by the same company and occupy the same building at 121 Mt. Auburn St., had worked without a contract until yesterday after their previous one-year pact expired Monday night.

Peter Finn, an attorney representing Ferdinand's, said management's action resulted from "a series of motives. We're trying to stay in business. The lockout helps in terms of trying to bring both sides together."

But the 25 workers, represented by Local 26 of the Hotel and Restaurant Workers Union, took a dimmer view of the action.

"It's an offensive against the workers," said the local's secretary-treasurer, Daniel F. Clifford, adding that the action "speaks to the inability of the employer to bargain collectively."

Both restaurants remained open throughout the picketing, after workers appearing for work between 3 and 5 p.m. were turned away. Managers said they will remain in business by using substitute labor.

"The employer can bring in scab workers, but they can't scab customers," Clifford said, predicting that business would fall off.

Picketers succeeded in discouraging about half of the restaurant's customers from entering, they estimated, but Manager Paul Keeler said it was "too early to tell" how much receipts had fallen.

Yesterday's dispute came about a year and a half after a month of picketing and negotiating won the employees membership in the union. That action followed the sudden dismissal of 13 workers in January 1982.

In picketing earlier in the day, union members said they sought a 25-cent wage hike from their $2.01 hourly wages, along with a more comprehensive benefits package. The union rejected management's first contract offer.