The Treasury Department has further trimmed its estimates of the amount of borrowing it will need to do this year as an improving economy has boosted tax revenues and cut spending needs more than previously expected.

Treasury said Monday that it now expects to borrow $1.438 trillion this year, still the second-highest amount in history. But that is down by 19.5 percent from last year's all-time record in borrowing of $1.786 trillion.

Late last month, the Obama administration lowered its estimate for the overall deficit for this budget year to $1.471 trillion. That would be the highest deficit in history, surpassing last year's $1.41 trillion deficit but is an improvement from the amount the administration had estimated in February.

After suffering through the deepest recession since the Great Depression, the economy began growing again in the third quarter of last year and that rebound, while anemic by normal standards, has boosted tax revenue above initial estimates and lowered spending demands for emergency programs below original estimates.

Because of these developments, Treasury announced Wednesday that it was reducing its borrowing estimate for the current July-September quarter to $350 billion, down from an estimate in May of $376 billion in borrowing needs for this quarter. Even with the improvement, borrowing this quarter will be the sixth-highest quarterly amount in history.

All the higher borrowing amounts have occurred over the past two years as the government has spent billions of dollars to cope with a deep recession and stabilize the financial system.

Treasury made the announcement on borrowing needs for July through September as part of its quarterly refunding process. It will provide details on the actual makeup of the securities that will be sold on Wednesday.

The government's budget year begins on Oct. 1 and will end on Sept. 30.

Treasury also gave a preliminary estimate that it will need to borrow $372 billion in the October-December period. That would be up from $260 billion borrowed in the same period a year ago. However, that figure was artificially lowered as Treasury maneuvered to keep from breaching the government's debt limit, giving Congress time to raise the figure. The debt limit now stands at $14.29 trillion.

The average of forecasts from Treasury's advisory committee of bond dealers puts this year's deficit at $1.351 trillion, lower than the administration's revised forecast of $1.471 trillion. For future years, the bond dealers are forecasting deficits of $1.207 trillion in 2011 and $997 billion in 2012. The 2011 figure is slightly lower than the administration's estimate but the 2012 forecast is higher.

The Obama administration, facing growing public unhappiness over the soaring budget deficits, has pledged to address those deficits in coming years. It has appointed a deficit commission that will make recommendations in December, after the November congressional elections, on ways to get the deficits under control.