BARTLESVILLE, Okla. (AP) _ In a vote that could determine whether Phillips Petroleum Co. remains independent, shareholders were to indicate today whether they support a company-backed recapitalization plan or Carl C. Icahn's bid to buy the company.

Icahn is a New York financier who launched a tender offer for Phillips two weeks ago, and he wants the company plan defeated so he can proceed with his $8.06 billion tender offer.

The meeting at the oil company's headquarters was scheduled for 10 a.m. CST, and Phillips officials said they had no idea how long it would last.

''We've never been through one like this before,'' said spokesman Bill Flesher.

About 3,500 people crowded into the corporate gymnasium and the overflow 700-seat auditorium was beginning to fill up as the start of the meeting drew closer.

While the shareholders entered the building, about 100 people carrying balloons and signs that said ''We Love Phillips'' marched outside.

Phillips has 154.6 million shares of common stock outstanding. Passage of the plan requires the support of more than 50 percent of the stock, or 78.8 million shares.

Among other things, the plan would restructure the amount of stock and debt on Phillips' balance sheet and significantly raise the number of Phillips shares owned by its employees.

For that reason, the plan would severely hamper an unwelcome takeover offer because the employees could use their stake to oppose such a bid.

The recapitalization plan is part of Phillips' agreement with an investor group led by T. Boone Pickens Jr., chairman of Mesa Petroleum Co., to end the group's takeover bid for Phillips launched in early December.

The Mesa group is obligated by the agreement to vote its block of 8.9 million Phillips shares in support of the Phillips recapitalization plan.

Since the Pickens group withdrew, Icahn has acquired 7.5 million shares of Phillips' stock, or 4.85 percent of the total, and has proposed a two-step plan to acquire the oil company.

The first step calls for Icahn to pay $60 a share for 70 million shares of the company's stock, or $4.2 billion in cash, which would give him a controlling 51 percent of the company. He then proposes to acquire the remaining shares with securities valued at $50 a share.

However, the offer is conditioned on Phillips' stockholders rejecting the company's recapitalization plan, and Icahn is soliciting votes against the plan.

Both Phillips and Icahn have been placing full-page newspaper advertisements to garner shareholder support for their positions.

Phillips stock has been among the most actively traded on the New York Stock Exchange since Icahn announced his intentions, but only shareholders of record Feb. 1 are eligible to vote at today's meeting.

Meanwhile, both sides have exchanged lawsuits in federal court in Tulsa to contest each other's efforts.

And Icahn's lawyers asked U.S. District Judge H. Dale Cook to delay today's meeting, but he did not do so.