Veteran forward Adrian Dantley, a free agent who has been without a team all season, signed yesterday with the Milwaukee Bucks, his agent, David Falk of Pro Serv, Inc., of Alexandria, Va., reported.

Dantley, a native of Washington who ranks among the National Basketball Association's all-time leading scorers, purchased his contract from the Dallas Mavericks after last season, but tried unsuccessfully to sell his services to another team.

But the Bucks felt an immediate need for a proven scorer when shooting guard Dale Ellis was diagnosed as having a herniated disk. Ellis could be lost for the rest of the season.

Dantley, 35, flew to Milwaukee yesterday morning and passed his physical. He then flew to Philadelphia to join the Bucks for last night's game against the 76ers, a team with which he had held lengthy but futile negotiations.