The Baltimore Orioles have been tantalizingly close to a trade for Houston Astros star right-handed slugger Glenn Davis for several days, but Doug Melvin, Baltimore's assistant general manager, said he does not anticipate anything happening until the new year.

Last night, the Orioles were guaranteed the return of their leading power hitter of the last two years when Mickey Tettleton agreed to the team's offer of arbitration.

A switch-hitting catcher, who had 26 home runs in 1989 and 15 last season, he could have become a free agent had he not accepted the Orioles offer.

Tettleton's numbers fell dramatically during the 1990 season. He hit just .233 with 15 home runs and 51 RBI with 106 walks and 160 strikeouts. He made $750,000 last season and tested the free agent market, apparently to no avail. He had been seeking a three-year deal worth $7 million.

Davis, 29, has been one of the National League's top power hitters, averaging 29 homers for the last five seasons while playing home games in the spacious Astrodome.

"Knowing that our needs are for some power and a legitimate RBI man, his name has been in the discussions," Melvin said.

The catch is, the Astros want four young players and the Orioles have, so far, found that too high a price. According to sources, the Astros want a starting pitcher (either Pete Harnisch or Bob Milacki), a set-up reliever (either Curt Schilling or Mark Williamson), a young outfielder (probably Steve Finley) and a minor league pitcher.

An Orioles-Astros trade is an almost perfect match for two reasons. The Orioles have a surplus of mediocre starters, outfielders and long relievers, plus lots of good minor league pitchers. And the Astros are holding a fire sale in preparation for John McMullen selling the team for as much as he can get.

The Astros already have lost free agents Franklin Stubbs and Dave Smith (199 career saves). Davis, who has one year left on his contract, could get McMullen several adequate, low-priced players. That way, the Astros could shrink their payroll in preparation for a sale while keeping the team from being a total laughingstock on the field.

From 1986 through 1989, Davis averaged 31 homers, 96 RBI and 155 games a season. Last season, injuries held him to 93 games, but he had 22 homers and 64 RBI.

The Orioles most likely can have him whenever they decide to give up the four players. The Astros want to keep their young players, but have no useful veterans to use as throw-ins to complete the trade.