TREASURIES-Slight price gains ahead of Fed meeting, debt sale

* Treasuries prices confined in a recent range

* Two-year note sale to kick off this week's auctions

* Investors looking ahead to Fed statement on Wednesday (Adds analysts' quotes, updates prices)

NEW YORK, Sept 22 - U.S. Treasury debt prices made slight gains but remained well within a recent range on Tuesday as the Federal Reserve prepared to start its two-day policy meeting.

Treasury debt traded higher despite looming supply as many traders anticipate strong demand at this week's auctions. The Treasury is set to sell a whopping $43 billion of two-year notes on Tuesday as part of $112 billion of debt supply this week.

Although there have been worries that the global appetite for large doses of U.S. government debt may eventually ebb and put pressure on prices for Treasuries, solid demand in similar auctions two weeks ago alleviated some of that concern.

"I was shocked at the demand in the last set of auctions, and that convinced me that that demand is not going to go away for a while," said William Larkin, fixed income portfolio manager at Cabot Money Management in Salem, Massachusetts.

Benchmark 10-year Treasury notes were trading 5/32 higher in price to yield 3.47 percent, down from 3.49 percent late on Monday. Early in the day the yield rose to 3.51 percent, marking the highest in nearly two weeks.

Traders noted Treasuries have traded in a fairly narrow range recently as the market grapples with billions of dollars in new supply while also trying to sort out the U.S. economic outlook.

"If there is something that's striking it's the fact that the range has been solid," said David Ader, head of government bond strategy at CRT Capital Group in Stamford, Connecticut. "Tens have played with 3.50 percent plus or minus about 11 times since the end of August and so far, held."

The 30-year bond was 5/32 higher to yield 4.23 percent from 4.24 percent late on Monday.

Ahead of Tuesday's auction, two-year notes were trading 1/32 higher in price to yield 0.97 percent, down from 1.00 percent late on Monday. When-issued two-year notes were yielding 1.03 percent.

While no one expects the Fed to lift interest rates from the current level near zero, investors will closely parse Wednesday's policy statement for any clues as to whether the U.S. central bank is mulling a winding down of its financial stimulus measures.

"The statement should be pretty cut and dry -- they should recognize that the economy is getting better, and may make mention of elongating the program to buy mortgages," said John Spinello, Treasury bond strategist at Jefferies & Co in New York.

Outside of the Treasuries market, stocks were trading a little higher, while the dollar on Tuesday hit a one-year low against the euro.