UPDATE 1-U.S. Treasury plans bigger debt auctions, warns on debt limit

(Adds details on debt auction plans)

WASHINGTON, Jan 31 (Reuters) - The U.S. Treasury on Wednesday said it plans to hold larger debt auctions due to the winding down of the Federal Reserve's bond buying program, but it warned that it would only be able to pay all of the federal government's bills through February.

"Based upon available information, Treasury expects to be able to fund the government through the end of February," Clay Berry, Treasury's deputy assistant secretary for capital markets, said in a statement. "Treasury urges Congress to act promptly on this important matter."

Treasury will exhaust all of its borrowing options and run dry of cash to pay its bills in March, the nonpartisan Congressional Budget Office said in December.

Berry said the fiscal outlook also played a role in Treasury's decision to sell more nominal coupon debt as well as two-year floating rate notes at weekly auctions.

Treasury anticipates increases in the sizes of two-year and three-year note auctions by $2 billion each per month over the next three months, beginning in February, Berry said.

It will also increase auction sizes for five-year, seven-year and 10-year notes as well as the 30-year bond, beginning in February, Berry said. (Reporting by Jason Lange; Editing by Paul Simao)