Keith Olbermann, the offbeat, acerbic ESPN “SportsCenter” anchor whose behavior over the past few months has tested the cable sports network’s management, will be let out of his contract six months before it expires, allowing him to pursue other jobs.His last day on the ESPN air will be June 29. The 38-year-old Olbermann’s contract runs through the end of 1997. He has been with the network since 1992, hired away from KCBS after also serving a stint as sports anchor at KTLA. Jean Sage, Olbermann’s agent, described the parting as “amicable,” though there has clearly been tension between Olbermann and the ESPN braintrust for quite some time. The chief reason for her client’s departure, she said, is geography. ESPN is headquartered in Bristol, Conn., and Olbermann wanted to live in New York. “We talked about several ways to get Keith to New York,” Sage said. “We tried to work out something that would be on a part-time basis so he could stay (at ESPN). We were not able to put together that deal.” But it seemed that Olbermann’s days at ESPN have been numbered since an August incident in which he appeared without permission on the Comedy Central program “The Daily Show,” hosted by former ESPN anchor Craig Kilborn. During that half-hour, Olbermann responded to the challenge, “Name the most God-forsaken place on the East Coast” with the reply “Bristol, Conn.” The appearance, and the slight of the town where ESPN is headquartered, did not sit well with the ESPN brass. Olbermann was forced to remain off the air for two weeks, from April 28 to May 12, as punishment, though at the time ESPN officials insisted it was not a suspension but “an opportunity for everyone involved to gain some perspective.” Olbermann had been seeking a re-negotiation of his ESPN contract. But it was more important to him to be able to move back to New York, a two-hour drive from Bristol. Among those that have already expressed interest in Olbermann’s services are Fox Sports and Court TV, where Olbermann’s good friend Erik Sorenson is a producer.