TREASURIES-U.S. prices inch up before Fed policy comments

* Early price gains dwindle

* Fed policy-shift worries ease (Adds late prices, market details and quotes)

By Michael Connor

NEW YORK, Sept 16 (Reuters) - U.S. Treasury debt prices inched up on Tuesday as investors in global markets throttled down fears that Federal Reserve policymakers meeting in Washington will soon undo America's ultra loose monetary policy.

After surrendering bigger price gains, driven in part by an independence referendum on Thursday in Scotland, yields on benchmark 10-year Treasury notes late on Tuesday were little changed at 2.582 percent. Prices were up 1/32.

Yields on 30-year Treasury bonds touched a low of 3.308 percent before rising as price gains reversed. The long bond was last off 5/32 in price and was yielding 3.35 percent.

Prices on shorter maturities were up as traders speculated about a two-day Fed policymaking session that ends on Wednesday with a policy statement and a potentially market-moving news conference by Fed Chair Janet Yellen.

"The market has pretty much determined that the message tomorrow is going to be continue to maintain (existing policies) for 'a considerable period,'" said Charles Comiskey, head of Treasury trading at Scotia Bank in New York. "That's why you are seeing a steepening of the curve and buying in the two-year, three-year and five-year notes."

The Fed on Wednesday will also release economic and interest rate projections, extending its forecast horizon through 2017.

It has said it does not expect to raise rates until 2015, but recent strong data has led Fed officials to acknowledge they may need to act sooner than they thought just a few months ago.

Some traders were squaring positions against unexpected changes at the Fed but most were betting on continued low rates, Comiskey said.

"What the market is telling you now is that there's not going to be much change in that statement," Comiskey said.

On Thursday, voters in Scotland will decide whether or not to end the 307-year union with England, possibly breaking up the United Kingdom. The polls show the result is too close to call.

"It's a Pandora (Other OTC: PNDZF - news) 's Box. What does it mean for the UK and the EU? What does it mean for other regions, like Catalonia in Spain?" asked Wilmer Stith, fixed income portfolio manager at Wilmington Trust in Baltimore, Maryland. "It opens more uncertainties, and the last thing Europe needs is more uncertainty." (Reporting By Michael Connor in New York; Editing by Peter Galloway and Grant McCool)