Nov. 6--Following a key vote Thursday night, the county of Marin and eight Marin municipalities have 90 days to decide whether to go forward with a plan to compete with Pacific Gas & Electric as a retailer of electricity in order to reduce Marin's greenhouse emissions.

The board of the Marin Energy Authority voted unanimously to approve a five-year draft contract. Shell Energy North America, a subsidiary of Royal Dutch Shell, is the lead bidder for the contract, but the authority still has the option of going with one of two other companies: Baltimore-based Constellation Energy Commodities Group or Houston-based Macquarie-Cook Power.

"This is a big milestone," said Marin County Supervisor Charles McGlashan, the chairman of the authority's board.

The authority, which consists of the county of Marin and all of Marin's cities except Novato, Larkspur and Corte Madera, was formed last year to explore projects to reduce greenhouse gas emissions. Chief among those projects is the Marin Clean Energy initiative, which calls for the authority to compete with PG&E as a retailer of electricity in Marin.

The government entities that make up the authority now have 90 more days to review the contract and decide whether they want to remain a part of the authority. A final vote on the contract is tentatively scheduled for Feb. 4.

"This is what we've always called the exit ramp," said Greg Stepanicich, the authority's attorney.

Only residents living in member jurisdictions will

have the opportunity of purchasing their power from the authority. Residents who wish to continue getting their power from PG&E will be allowed to opt out.

The contract will be executed only if the wholesale provider can guarantee Marin customers that at least 25 percent of their electricity will come from renewable sources while at least matching PG&E prices. Customers who are willing to pay a slightly higher premium will also have the option of assuring that 100 percent of their electricity comes from renewable sources.

PG&E expects to fall about 5 percent short of meeting the state-mandated requirement of getting 20 percent of its energy from renewable sources by 2010. Company representatives say transmission is a barrier. Only a handful of people addressed the board prior to the vote. Two of them were representatives of PG&E.

"This $350 million draft contract is one of the largest expansions of government in Marin in decades," said PG&E spokeswoman Katie Kerns.