More than 50 Indian tribes in California signed an agreement with the state today to keep open and even expand their profitable casinos, a pact that could greatly affect the growing gambling industry in the West.

The fate of the casinos, which are scattered on reservations across the state, had been in jeopardy since last month, when the California Supreme Court ruled that the state's constitution banned that form of gambling, even on reservations.

But in California the governor has the legal right to enter into an agreement despite the Supreme Court ruling. That decision overturned Proposition 5, a ballot initiative that California voters approved last year to give the tribes the right to run poker games and slot machines on their land.

That ballot battle was the most expensive ever waged in California. About $100 million was spent on the ballot question, two-thirds of it by a coalition of California tribes. The campaign pitted the tribes against powerful casino interests from neighboring Nevada, which view the emerging Indian gaming industry as a potentially serious threat.

Tribal leaders in California called the agreement their most significant victory yet.

Daniel Tucker, vice chairman of the Sycuan Band of Mission Indians, said that the pact "will finally allow California Indian tribes to achieve the self-reliance that we have long been seeking."

California Gov. Gray Davis (D), who has been negotiating with tribes for weeks, said he was satisfied with the compromises in the deal. "It balances the interests of the Indian people and the other people of this great state," he said. "And for those tribes that adopt it, this compact offers security and economic promise."

Despite today's agreement, the fight over Indian gambling in California may not be over.

The Indian tribe that runs that largest casino in the state, in Palm Springs, did not sign the pact, objecting to key parts that it said could pit tribes against each other. The tribe is vowing instead to take the issue directly to California voters again next spring when a constitutional amendment about the matter may be on the ballot.

Moreover, state officials and tribal leaders deferred for another month a decision on what kind of union organizing rights casino workers should have, a difficult issue in their talks. The 20-year pact will be nullified unless both sides reach agreement on the labor issues by mid-October. The casinos employ about 15,000 workers.

In all, 58 California tribes signed the agreement, which will allow them to maintain the nearly 40 casinos that are now on reservations. The pact could double the number of slot machines tribes are allowed to have to about 43,000. Tribes that do not have gaming can deploy as many as 350 slot machines each; no tribe can have more than 2,000 machines.

The pact also contains a revenue-sharing provision that could divide $55 million a year among California tribes without casinos. The state will get a small portion of the casino money.

Revenue from reservation casinos has been a boon for California tribes. The profits are also making some tribal members millionaires, and important new political players in the state. In 1998, three of the top 10 contributors to state legislators and legislative candidates were California Indian tribes.