OLYMPIA, Wash. (AP) _ Republican Sen. Slade Gorton's lead over challenger Maria Cantwell narrowed Tuesday as more absentee ballots were counted in the nation's last unsettled Senate race, including thousands from the heavily Democratic Seattle area.

With more than 140,000 new ballots tallied Tuesday in 16 of the state's 39 counties, Gorton clung to a 3,782-vote margin, a net loss of about 10,000 votes from Monday's totals.

The latest tally was 1,083,154, or 48.8 percent, for Gorton; 1,079,372, or 48.63 percent, for Cantwell; and 57,001, or 2.56 percent, for Jeff Jared, the Libertarian candidate.

About 200,000 votes remain untallied. More than 2.2 million have been counted.

Now, more than a week after Election Day, both sides are beginning to talk about the likelihood of an automatic recount, which is required by state law if the race ends with a margin of less than one-half of 1 percent separating the candidates, or about 12,000 votes.

``It's down to the bottom of the 9th inning, and we're hoping for a grand-slam home run,'' said Ellis Conklin, spokesman for Cantwell. He said the whole race boils down to about 60,000 or 70,000 ballots that will be counted in King County, which includes Seattle, on Friday.

The Gorton campaign continues to believe that the senator's strong support in the rest of the state will be enough to offset Cantwell's Seattle-area base.

``We're optimistic, but this is going to be close,'' spokeswoman Heidi Kelly said.

Gorton, 72, is seeking his fourth six-year term, touting his seniority and budget-writing leadership post in the Senate. Cantwell, 42, a former six-year veteran of the state House and a one-term member of the U.S. House, has called Gorton out-of-touch and too willing to threaten the environment to create new jobs. A high-tech millionaire, she largely financed her own campaign.

On Tuesday, she nearly closed the statewide gap by gaining 55,720 more votes in King, versus Gorton's increase of 40,368. Overall, her edge in the county is 138,440 votes, up from an election night margin of about 109,000 votes in King.

Gorton has not trailed since Election Day.

A Cantwell victory would usher in a 50-50 tie in the Senate for the first time in a century, down from the pre-election GOP margin of 54-46. But if Al Gore wins the White House and his vice president, Sen. Joe Lieberman of Connecticut, turns over his seat to a Republican appointee, the GOP membership would rise to 51 seats.

If George W. Bush wins the White House, his vice president, Dick Cheney, would be able to break ties in a 50-50 Senate. If Gorton wins, the Republicans get 51 seats. If Gorton and Gore win, the GOP will have 52 seats.