The U.S. federal budget deficit reached nearly $1.4 trillion by the end of August, with one month remaining in the worst fiscal year for the federal government in history.

The nonpartisan Congressional Budget Office said Tuesday the deficit reached $1.38 trillion through August, with revenue running 16% lower than in fiscal 2008, while federal outlays were running 19% higher.

Last month, in a revised budget outlook, the CBO said it expected the budget deficit to top out at $1.6 trillion by the end of September, slightly improved from its earlier forecast of $1.8 trillion for the fiscal year.

The CBO said the federal government had spent or seen a decrease of revenue worth $150 billion stemming from the economic stimulus plan, while $83 billion of public money has been used to prop up Fannie Mae (FNM) and Freddie Mac (FRE).

-By Corey Boles, Dow Jones Newswires; 202-862-6601; corey.boles@dowjones.com