TREASURIES-Yields near three-week lows before Fed buybacks

* Benchmark 10-year note yields trade near three-week lows

* Fed plans two buybacks in Operation Twist

* Traders expect Fed to announce new QE at next week's meeting

NEW YORK, Dec 6 (Reuters) - U.S. benchmark Treasury yields dipped to near their lowest in three weeks on Thursday, supported by expectations the Federal Reserve will announce a new bond purchase program when it meets next week. The Fed is making two bond purchases on Thursday as part of its Operation Twist program, which involves buying long-term debt, and funding the purchases with sales of short-dated notes. The program is scheduled to expire at the end of the year, when traders expect the Fed will instead make outright purchases of longer-dated Treasuries as it runs out of short-dated debt to sell. "People may starting to trade on expectations that once Operation Twist ends, the next QE will be buying intermediate and longer-dated securities without selling the front-end," said James Newman, head of Treasuries and Agency trading at Keefe, Bruyette and Woods in New York. Buybacks on Thursday will include between $1.50 billion and $2.25 billion in debt due between 2036 and 2042, and $4.25 billion to $5.25 billion in notes due from 2018 to 2020. Treasuries gained even as more positive signs emerged in Washington that lawmakers will reach a deal to stave off a fiscal crunch at year-end, when a combination of spending cuts and tax increases threatens to harm the economic recovery. While Republican leaders in the House of Representatives insist that raising tax rates on the rich is an impossibility, some Republican lawmakers now see it as inevitable to avoiding the "fiscal cliff" of severe tax hikes and spending cuts set to start in January. Further progress in reaching a deal may hurt Treasuries, as less uncertainty would make the safe haven assets less attractive. "We're getting a very positive vibe out of Washington with some Republicans crossing over to support Obama's budget plan, which leads us to believe that the long-end of the curve should be selling off and we should be steepening," said Newman. Benchmark 10-year Treasuries were last up 5/32 in price to yield 1.57 percent, down from 1.59 percent late on Wednesday. Thirty-year bonds gained 15/32 in price to yield 2.76 percent, down from 2.78 percent. Bonds showed little reaction to data that showed that the number of Americans filing new claims for unemployment benefits fell for a third straight week last week. Investors are also focused on the release on Friday of government's monthly payrolls report for November, which is expected to show that employers added 93,000 jobs in the month, according to the median estimate of economists polled by Reuters.