The Baltimore Orioles have requested a one-year extension of their lease at Memorial Stadium and expect to play at least 68 games there next season.

According to Edward Bennett Williams, owner of the Orioles, the extension would commit the ball club to 68 games in Baltimore. "We have the right to play 13 in Washington -- the same as last year," he said.

Asked if there was any change in the situation regarding playing 13 games in Washington for 1981 season, he said, "Not at this point. There's nothing new on that."

According to Douglas Tawney, Baltimore director of Parks and Recreation, "The Orioles wrote us a letter last week and asked to renew (the lease) for 1981 at the same terms as this season . . . We will accept their offer."

Williams said, "It was exactly the same letter we wrote last year. We asked to renew for one year only. We have not heard yet."

The deadline for the Orioles to make their intentions clear for the 1981 season was yesterday. General Manager Hank Peters said he expected the Orioles "to be nesting in the same place" in 1981.

The Orioles signed a seven-year lease to play in Memorial Stadium in 1977, with an option to renew or withdraw from the lease every other year.

According to Tawney, the lease stipulates that "if the Orioles desire to alter the terms or not play here, they have to tell us by June 30. Last year, with the two-year period ending, they said, 'We don't want to renew for two years, we want to renew for one.'"

The parks board and the Board of Estimate agreed to that proposal last year, and Peters said he "anticipated no problem" in getting their approval again.

Williams said he believed that if the Orioles had not made this request for a one-year extension, "we would automatically trigger a two-year renewal."

Tawney said that had the Orioles done nothing by the June 30 deadline, "two more years on the contract would become automatic."

Tawney added that the parks board was very happy with the arrangement, but could be happier.

"We'd rather have a 10-year lease." he said. "And we'd rather have a 15-year lease than a 10-year lease. But this is the situation.

"Mr. Williams' wants to go year by year. He has said that as long as attendance holds up they will stay in Baltimore. So far, his actions follow his words."

Asked why he thought Williams wanted a year-by-year arrangement, Tawney said, "You'll have to ask him."

Williams said, "It's the way most things are done, on a year-by-year basis."

After 34 home games, the Orioles attendance this year is 617,386, 67,994 fewer than last year. The average attendence so far this year is 18,158, exactly 2,000 a game fewer than 1979.

Although the parks board might prefer a longer lease, it doesn't have much choice but to accept the Orioles' year-by-year formula.

"That's true," said Tawney. "You can't make a franchise stay in a city, as has been demonstrated by many having moved. But Mr. Williams has said they will stay as long as attendance is satisfactory. We're only 66,000 off our banner season and the Orioles haven't played well until recently.

"Just tell 'em" he said, "Washington ain't getting our team."