Dallas ? As the free-agent negotiating period began Tuesday, Mavericks owner Mark Cuban announced a different kind of deal — a three-year contract extension for Don Nelson to remain coach.

Nelson already was under contract as general manager through 2005-06. Now he’ll keep both jobs that long, continuing a double duty he began in the 1997-98 season.

“The bottom line was I wanted to remain the coach of the Mavericks,” Nelson said. “I believe I am the right person for the job and look forward to building on our recent successes.”

Nelson asked for an extension early this past season when Dallas held the best record in the NBA. Cuban said he wanted to wait until after the playoffs. The Mavericks went on to win a franchise-record 60 games, then reached the Western Conference finals.

The 63-year-old Nelson is the third-winningest coach in NBA history, having gone 1,096-828 in 25 seasons with Dallas, Milwaukee, Golden State and the New York Knicks. The Mavericks are 245-199 since he fired Jim Cleamons and took over himself, months after being hired as GM.