The Senate voted overwhelmingly yesterday to confirm Richard C. Holbrooke as ambassador to the United Nations, ending a lengthy effort by Republicans to hold the nomination hostage while they sought concessions from President Clinton on other issues.

Despite months of political maneuvering, Holbrooke, 58, a veteran diplomat and troubleshooter who has played a key role in Balkan diplomacy, was confirmed 81 to 16 after only a half-hour's debate.

Holbrooke's confirmation troubles underscored the sour relations between Republican leaders and the White House and dramatized the GOP's increasing use of delaying tactics to force the administration to heed the party's demands. Such tactics, coupled with a lengthy ethics investigation, helped keep one of the country's most important diplomatic posts open for nearly a year.

The U.N. post has been empty since last September, when Bill Richardson left to head the Energy Department. In recent weeks, the Senate's GOP leadership ran into increasing criticism from senators of both parties and the Pentagon for leaving the post vacant at a critical juncture in U.N.-led efforts to create a stable new government in Kosovo.

Both Clinton and Holbrooke issued statements saying they were "deeply gratified" by the Senate's action. Clinton praised Holbrooke's "commitment to public service and especially for his willingness to persevere through the . . . process."

Among those voting against the confirmation were Majority Leader Trent Lott (R-Miss.), Assistant Majority Leader Don Nickles (R-Okla.) and most other top GOP leaders, all of whom have been sharply critical of the president's foreign policy, especially toward the Balkans.

Holbrooke is a former ambassador to Germany and assistant secretary of state who brokered the 1995 peace agreement in Bosnia. During the brief Senate debate yesterday, he was hailed as eminently qualified for the U.N. post by several Democrats and Armed Services Committee Chairman John W. Warner (R-Va.), who had been prodding the GOP leadership to act on the nomination.

Warner said Holbrooke was "better qualified than anyone I know of to undertake this mission."

Sen. Kay Bailey Hutchison (R-Tex.), the only senator to speak out against his confirmation, said she regarded Holbrooke as a "principled man" and admired his "tenacity" but opposed his "foreign policy principles" as a danger to national security. In the Balkans, in particular, she said, he would "force factions to live together in an American model" despite vastly different circumstances.

Several Democrats lashed out at the tradition of "holds," under which any senator can block action on legislation or a nomination so long as the majority leader agrees to honor it. In Holbrooke's case, Lott did so for more than a month. It is an "abuse of power" to hold up nominees to force deals on unrelated issues, argued Sen. Joseph R. Biden Jr. (D-Del.). The way was cleared for Holbrooke's confirmation Wednesday when Sen. Charles E. Grassley (R-Iowa) switched his "hold" from Holbrooke to three other ambassador-designates, still hoping to force changes in whistle-blower practices at the State Department. Among them was A. Peter Burleigh, who is filling in for Holbrooke at the United Nations and awaiting an ambassadorial post in the Philippines.

Holbrooke's long wait started shortly after Clinton chose him 14 months ago, when questions were raised about possible conflicts of interest in his work as an investment banker between his diplomatic assignments, triggering an eight-month inquiry within the government. When these questions were resolved last spring, the Foreign Relations Committee approved the nomination and sent it to the full Senate, where other problems quickly emerged.

After Grassley filed his "hold," Sen. Mitch McConnell (R-Ky.), backed by Lott, followed suit in an attempt to force the White House to accept their choice for a Republican seat on the Federal Election Commission. Their candidate, Bradley A. Smith, an Ohio law school professor, has been sharply critical of Clinton and campaign finance reform.

Sen. George V. Voinovich (R-Ohio) also briefly delayed action because of U.S. policy in the Balkans and Holbrooke's role in it.

It was not clear how much, if anything, the Republicans gained from their effort to use Holbrooke's nomination to achieve other ends.

Grassley contended he had made "some progress" toward whistle-blower protections but wanted more. Asked about the FEC appointment, McConnell said, "We're working on it." There was no discernible change in Balkan policy as a result of Voinovich's objections. All three senators voted for Holbrooke's confirmation.