The Washington Redskins announced yesterday that they have reached agreement with center/guard Rick Donnalley on a new contract and have signed reserve quarterback Babe Laufenberg to a series of one-year contracts.

The Redskins acquired Donnalley, 6 feet 2, 270 pounds, from the Pittsburgh Steelers before the 1984 season. He replaced starting center Jeff Bostic when Bostic went out with a knee injury midway through the season. Laufenberg, 6-2, 196, a 1983 draftee out of Indiana, spent last season on injured reserve with a sore shoulder.

Terms of the contracts were not disclosed . . .

A four-year collective bargaining agreement between the United States Football League and its players was approved by both sides last night after nine months of negotiations.

Major provisions provide a minimum salary of $22,500; major medical, life and dental insurance for players and dependents; increased preseason and postseason pay, and independent arbitration for grievances . . .

A vigil to mourn the first anniversary of the night the NFL Colts packed up and secretly moved from Baltimore to Indianapolis drew only about three dozen fans. Those who showed Thursday night in front of Memorial Stadium to shout old cheers and light candles said it didn't matter.

"We're calling it the Mayflower Night because the Mayflower moving trucks pulled up in the middle of the night and took the Colts," said Gil Griggs, the event organizer.