A controversial bill bestowing sweeping antitrust immunity on the U.S. liner shipping fleet sailed through the Senate yesterday after its strongest opponent, Sen. Howard Metzenbaum (D-Ohio), abandoned an effort to kill it by filibuster.

The 64 to 33 vote represented a major victory for ship operators and maritime industry lobbyists, who said the measure is necessary to enable this country's dwindling merchant fleet to compete for cargo on international routes.

A similar bill was passed overwhelmingly in the House last year. Sen. Slade Gorton (R-Wash.), a leading sponsor of the bill, predicted "quick action" by the House this year, resulting in an early House-Senate conference and a bill that President Reagan will sign.

The administration has supported the measure as part of its maritime deregulation program. Transportation Secretary Elizabeth Hansford Dole said yesterday that the bill "moves us closer to long-needed regulatory reform of ocean-liner shipping." She called it "an important step toward President Reagan's goal of a revitalized merchant marine."

Metzenbaum and the bill's other chief opponent, Sen. Orrin Hatch (R-Utah), argued in vain that the bill would give ship operators a free hand to set rates and would result in higher shipping costs, without increasing the 27 percent share of this country's international liner tonnage carried by American-flag vessels.

Metzenbaum gave up his filibuster a few hours before a scheduled cloture vote because he saw "no ultimate possibility of victory, no way to achieve anything except delay," he said later.

As passed after several amendments, the bill would allow the operators of U.S.-registered liner vessels, or freighters carrying general cargo on scheduled routes, to participate in the rate-setting activities of international groups of shipping companies known as conferences without fear of antitrust action. Conference members also would be allowed to pool their revenues, which Metzenbaum charged would enable them to "lowball" independent competitors.