NEW YORK, JAN. 22 -- A federal judge today blocked Trans World Airlines Inc. Chairman Carl C. Icahn from submitting his own bankruptcy reorganization plan to Texaco Inc. shareholders, setting the stage for an important vote next month on Texaco's proposed legal settlement with Pennzoil Co.

Icahn, who controls about 15 percent of Texaco's stock, had asked Judge Howard Schwartzberg for permission to submit to shareholders an alternative settlement plan that would have stripped the oil company of many of its takeover defenses. But Schwartzberg, who oversees Texaco's bankruptcy reorganization, ruled that bankruptcy proceedings were not the proper forum for a dispute over corporate control.

Apart from its takeover provisions, Icahn's plan would have been identical to the proposed settlement of Texaco's $10.3 billion legal dispute with Pennzoil, which was reached following intensive negotiations last December. The key element of the proposed deal, which if approved would permit Texaco to emerge from bankruptcy, is a $3 billion cash payment by Texaco to Pennzoil.

The settlement plan requires two-thirds approval by those Texaco shareholders who cast ballots. Icahn testified at a bankruptcy hearing Wednesday that he would "without question" vote against the plan if he was not allowed to submit an alternative settlement to shareholders.

If Icahn follows through on that threat when the ballots are cast -- and attorneys for Texaco and Pennzoil suggested Wednesday that Icahn would change his mind when confronted with a final decision -- he may succeed in scuttling the deal between Texaco and Pennzoil, forcing the two companies to press their legal appeals before the U.S. Supreme Court. But if Icahn pursues that course, he will have significant legal obstacles to overcome.

For one thing, even if the proposed settlement fails to attract a two-thirds majority of Texaco shareholders, it may still be approved by Schwartzberg under so-called "cram-down" provisions of the bankruptcy code. Harvey Miller, Texaco's lead bankruptcy counsel, said he is confident such approval could be obtained over Icahn's objections.

To obtain a cram-down approval, Miller said, "You have to comply with the statutory standards, that the plan does not unfairly discriminate and is fair and equitable, which would be real easy to do in the case of Texaco ... I don't think he {Icahn} could resist it."

"We are naturally disappointed with the decision," Icahn said. "We continue to believe that shareholders are being strong-armed by Texaco's management. We intend to study the court's decision and re-evaluate all the options at our disposal."

In a statement, Texaco called Schwartzberg's ruling "an important and significant step toward allowing Texaco to return to competitive leadership." The company said that Icahn "now has an opportunity to participate in constructive efforts to make Texaco stronger."

Even if he did succeed in unraveling the pending settlement, Icahn risks losing hundreds of millions of dollars if Texaco loses before the Supreme Court. Icahn testified Wednesday that some of his investment in Texaco was made with borrowed funds, meaning that a sudden decline in Texaco's share price could cause him severe financial pressures. By the same token, Icahn could reap a huge windfall if Texaco were to eventually win its appeal.

Pennzoil's record $10.3 billion judgment was awarded by a jury as compensation for Texaco's alleged interference with a 1984 merger contract. The award has already been affirmed by the Texas appeals courts. The U.S. Supreme Court is Texaco's last opportunity to reverse Pennzoil's judgment, but the high court has no obligation to even consider Texaco's appeal.

The next step in the voting process is a bankruptcy hearing scheduled for next Wednesday at which Schwartzberg is expected to approve a final disclosure statement designed to provide shareholders with details about the proposed settlement plan. Once the disclosure statement is final, ballots will be sent out to shareholders. The voting is expected to conclude in late March.

Icahn sought to submit an alternative plan to shareholders now in part because everyone involved in the Texaco bankruptcy case is facing acute time pressures. Provisions of the settlement with Pennzoil and the timetable of Texaco's Supreme Court appeal require that the deal become final by April. Otherwise, the settlement would be voided.