The state Supreme Court today gave Gov. Linda Lingle 30 days to replace six members of the University of Hawai'i Board of Regents that the governor has kept on the board as holdovers since their terms expired at the end of June.

The court's order stems from an extraordinary legal challenge by the state Senate, which argued that Lingle was improperly keeping the regents as holdovers. One of the holdovers was Kitty Lagareta, a communications executive and the governor's friend and former political adviser, who was rejected for a second term on the board by the Senate in May.

Lingle's regent nominations will be subject to Senate confirmation.

The court's order came just a few hours after justices heard arguments in the case this morning.

Deputy attorney general Charlene Aina, who represented Lingle, argued that state law allows the holdovers to serve until their replacements are confirmed by the Senate. Aina contended that the governor could theoretically keep the holdovers on the board until her term expires in 2010.

But Jon Van Dyke, a UH-Manoa constitutional law professor who represented the Senate, said Lingle had until the end of June to nominate replacements and was manipulating the law for her favored regents. He said there is a cloud over board decisions because the six regents should not have remained as holdovers.

"It's clear that she's manipulating the process," Van Dyke told the court.

Several justices pressed Aina to describe what the state considered a reasonable amount of time for the governor to make the nominations. Aina declined to be specific but said case law suggested that two or three years would be reasonable and state law generally allows holdovers on boards and commissions to remain for two legislative sessions.

Asked by Associate Justice Steven Levinson whether the holdovers could remain until Lingle completes her term in 2010, Aina replied: "It's a factual possibility."

Voters approved a constitutional amendment in 2006 that called for an advisory council to recommend potential regent nominees to the governor, who previously had sole discretion to chose nominees. The state Legislature created an advisory council over Lingle's veto in 2007.

In February, the advisory council provided Lingle with a list of potential regent nominations to fill a dozen vacancies on the 15-member board.

Lingle made several regent nominations, including some who were confirmed by the Senate. But Lagareta -- who was not confirmed -- and five other regents were not replaced by the time their terms expired at the end of June.

The Senate objected to the governor's decision to keep the six regents on as holdovers and filed a legal challenge, known as a writ of mandamus.

Such writs are considered extraordinary legal remedies. The conflict between the Senate and the governor also posed separation of powers questions between the legislative and executive branches of state government.