Phillips Petroleum Co. will put its future in the hands of its shareholders today, asking them to vote for a complicated, controversial recapitalization of the company -- defeat of which could lead to a takeover of Phillips by financier Carl C. Icahn.

Phillips has said it is confident of winning the recapitalization vote, to be held at a shareholders meeting at its corporate headquarters in Bartlesville, Okla. But some analysts say it may be close. Some large Phillips shareholders, including Batterymarch Financial Management and the New York City Pension Fund, have said they will vote against the company's plan.

The Los Angeles Times reported last night that Minneapolis financier Irwin L. Jacobs said he would join Icahn in voting his reported 4.6 million shares, an estimated 3 percent stake in the company, against the proposal.

The plan needs every vote it can get, because an abstention from balloting is equivalent to a vote against it. Phillips officials have been aggressively soliciting votes for the proposal through newspaper ads and phone calls to stockholders.

Under the recapitalization, Phillips will go heavily into debt to buy back nearly 40 percent of its outstanding shares, and purchase more in the future. It also will sell shares to an employe stock ownership plan, and sell nearly $2 billion worth of assets. Phillips officials claim the plan will keep the company's stock at about $53 a share, but Wall Street analysts put the value at more like $50 a share. Icahn has charged it will be even less.

Icahn, who owns just less than 5 percent of the company, has said he will offer $60 a share for a half interest in Phillips, and $50 a share for the rest in a deal worth a total of $8.5 billion. But he has conditioned that offer on shareholder rejection of the recapitalization. It is not clear what Icahn would do if the recapitalization is approved, but he is also attempting to call a shareholders meeting for a later date for a proxy contest in which he seeks to replace the Phillips board with directors of his own choosing and take over the company in that fashion.

Phillips has questioned Icahn's ability to raise enough money to buy the company, but Icahn says he already has raised $1.5 billion and is confident he can get more.

One block of votes Phillips is sure of at the meeting is the 5.8 percent stake held by a group headed by Mesa Petroleum Co. Chairman T. Boone Pickens Jr. Pickens agreed to vote for the recapitalization as part of a truce that ended his attempt to take over Phillips last December, even though he has since criticized some actions taken by Phillips to ward off Icahn.