STEVE RINGMAN / THE SEATTLE TIMES

"What's being done to the Sonics is criminal, and each of these is to blame," says Peter White, at right, who with Lance Thompson, Chris Erickson and Karl Erickson, all of Seattle, wear jail stripes Sunday at the Sonics' last home game of the season. Their signs refer to owner Clay Bennett; Oklahoma City, where he wants to move the team; former owner Howard Schultz; and NBA Commissioner David Stern. The Sonics beat Dallas 99-95.

SEATTLE - Lawyers for the Seattle SuperSonics open the trial brief for their upcoming court battle with the city of Seattle with words that succinctly summarize why the team feels it should begin playing in Oklahoma City next season.

"Leases are generally not specifically enforceable," reads the first sentence of the Sonics' brief, obtained by The Associated Press on Wednesday night after it was filed in federal court in advance of a trial set to begin here Monday.

The Sonics, Seattle's oldest professional sports franchise with 41 years in town, are seeking to break the final two years of their lease at KeyArena by paying the city a sum the team believes would satisfy the arena agreement. The city argues the lease requires "specific performance," that is, the Sonics need to play in KeyArena through the 2009-2010 season.

U.S. District Judge Marsha Pechman is presiding over the trial, expected to wrap up June 26.

"Damages in the form of rent make the landlord whole," the Sonics' brief states. "... The facts show it is time to end the relationship (with the city of Seattle), not continue it by force. Both parties will be worse off financially with forced performance, and there is no offsetting benefit."

In a deposition taken in April, Sonics owner Clay Bennett testified he and his co-owners would lose between $61 million and $65 million if forced to play in Seattle for two "lame-duck" seasons. Bennett said the Sonics would make $18.8 million should the court allow the team to play in his hometown beginning this fall.

"While the city relies on the interests of the public at large, the public is not a party to the lease. As nonparties, their interests are legally irrelevant," the team's brief states, jabbing a legal stick at Seattle's professional basketball fans.

"The great majority of the public has a yawning indifference to the Sonics' departure," the brief adds.

While attendance decreased last season, the team still drew an average of 13,355 fans per game -- 78 percent of capacity in the NBA's smallest venue.

The brief, filed for Bennett's Professional Basketball Club LLC, also warned that if Pechman rules against the Sonics, she will be creating more work for her court.

"If forced to stay, the PBC may be forced to drastically alter its business methods," the team said. "There is little doubt that this would involve the court in a challenge to the team's business methods."

The team also reiterated its belief Seattle is acting with "unclean hands," again alleging the city is trying through "forced bleeding" to push Bennett into selling to more Seattle-friendly investors -- such as previously interested Microsoft Corp. Chief Executive Steve Ballmer, who is not mentioned by name in the brief.

The brief also reminded the court that the Sonics under Bennett's ownership will leave Seattle after the lease expires in 2010 anyway, since the NBA has already approved the team's move to Oklahoma City.