The Safeway supermarket chain and its striking Teamsters Union truck drivers reached a tentative contract settlement yesterday, just four hours after resuming negotiations.

Union bargainers unanimously agreed to recommend that the 260 Safeway workers who belong to Local 639 ratify the proposal at a 2 p.m. meeting today, according to Charles Scott, a commissioner for the Federal Mediation and Conciliation Service who presided over yesterday's negotiations.

"We're . . . confident that the people will ratify it" and end the four-day-old strike, Scott said.

Neither Safeway nor union officials would disclose details of the settlement until union leaders have a chance to discuss them with the rank-and-file members.

But, Scott said, both sides made "sincere concessions to get this thing settled. Obviously, neither got totally what they wanted, but that's the name of labor negotiations."

Safeway spokesman Ernie Moore said the food chain is "cautiously optimistic it's settled. We think it's a good agreement."

Safeway's truck drivers, garage personnel and truck loaders, who work out of the company's main distribution center in Landover, struck the company Sunday after unanimously rejecting a proposal that would have raised their salaries from $14 to $15.70 an hour over the three-year life of the contract.

Drivers for the Giant Food chain overwhelmingly accepted the same pay increase.

But Safeway's truckers objected to a company demand that they start unhitching their trailers filled with food when they deliver them to 151 stores from southern Pennsylvania to Fredericksburg, Va.

Safeway wants to have them unloaded at its convenience, and by workers who are paid less than the truck drivers.

Safeway drivers currently unload their own trucks, but management claims that it needs to make the change in order to stay competitive with its chief rival in this region, Giant Food.

Giant's trucks are already unloaded by store personnel, not truckers. The Safeway union argued that the change in work rules would eliminate up to 80 jobs.

It was not known how the dispute was settled, but Local 639's president, Phillip Feaster, said earlier this week that the union was willing to negotiate on the truck-unloading item, if the company offered job security for the truckers.

Also, Local 639 was contesting the attempt to supply a store in Fredericksburg from its Richmond center, rather than Landover.

While union members have picketed the Landover center since Sunday, Safeway's Moore said the strike has had no effect on the quantity of food in the stores.

Under the expired pact, driverswere required to deliver perishables until 1:15 p.m. today.

"We've had no disruption in service to our stores," Moore said.

If the contract is not ratified, Safeway has said that it will use managers and hired drivers to deliver products to its grocery stores.