The U.S. federal budget deficit fell to $161 billion in fiscal 2007 from $248 billion the prior year as growth in tax receipts, fueled by capital gains and other non-withheld income, outstripped spending growth, the Congressional Budget Office said on Friday.

The CBO said in its monthly budget review that the federal government ended its fiscal year on Sept. 30 with a $113 billion budget surplus for September, an increase of $57 billion over the September 2006 surplus.

The CBO's final full year 2007 deficit estimate was $3 billion larger than its previous estimate of $158 billion, made in August, as both revenues and outlays ended the year slightly less than it had forecast.

The U.S. Treasury is expected to release its final fiscal 2007 budget data on Wednesday. The White House budget office has previously estimated a significantly larger fiscal 2007 deficit of about $205 billion.

A final figure matching either estimate would a mark a third year of decline for the federal deficit since it hit a record of $413 billion in 2004.