After more than 20 months of delay, a court of appeals in San Francisco ruled yesterday that the campus can begin construction of a controversial athletic center at Memorial Stadium.

The decision means UC Berkeley can begin removing the trees at the construction site that have been occupied since December 2006 by tree-sitters protesting the campus's plan.

Campus officials said they had yet to decide the next step in removing the four remaining tree-sitters but plan to issue a 72-hour ultimatum before they attempt a removal.

Tree-sit supporters said they expected imminent action by UCPD.

In an effort to prevent the trees from being removed, Stephan Volker, an attorney for the California Oak Foundation and one of the plaintiffs in the suit, said he would ask the California Supreme Court today for an emergency injunction to prevent construction.

However, Richard Frank, the executive director of the California Center for Environmental Law and Policy at Boalt Hall School of Law, said it was highly unlikely the Supreme Court would grant an injunction in a case like this.

Three groups-the city of Berkeley, the Panoramic Hill Association and the foundation-sued the university in December 2006, seeking to prevent the construction of the proposed athletic center near the stadium. The case was heard by Alameda County Superior Court Judge Barbara Miller, who last week reaffirmed her final ruling, a win for the campus.

Two plaintiffs, the foundation and the association, then appealed that decision.

The appellate court decided yesterday to hear the appeal but still allow construction to begin. The appeal is expected to be heard in the next 10 to 18 months.

Dan Mogulof, the campus's executive director of public affairs, said he was pleased the campus could finally begin construction.

"It's a great day," he said. "It took us over 20 months and now two courts have been heard from. We're delighted."

But UC Berkeley sophomore Laura Zelko, a tree-sit supporter, said she was ready to fight outside the courts.

"I'm very disappointed with the ruling," she said. "However, when the court system lets us down, the people need to step up and say what is right."

Zelko and her fellow tree-sit supporters said last night they would maintain an all-night vigil at the grove near the stadium.

Michael Kelly, the president of the Panoramic Hill Association, said he was not concerned about the recent decision because he feels his group will eventually prevail.

"Our case for appeal remains strong, and we look forward to arguing before the Appellate Court next year," he said in a statement. "In the meantime, if the University does begin construction on the training center, they essentially do so at their own risk."

But Frank said he thought the court's decision today could reflect their final opinion.

"I don't think it is a definitive signal, but it certainly is a signal," he said. "One can infer the court has made a preliminary opinion."

Tags: MEMORIAL STADIUM, ATHLETIC CENTER LAWSUITS, OAK GROVE