(Reuters) - The U.S. Treasury said on Monday it expects to borrow $243 billion in the second quarter, $41 billion more than the January estimate largely due to lower cash receipts, partially offset by a higher cash balance at the beginning of the quarter.

The second-quarter financing estimate assumes a cash balance of $750 billion at the end of June, the Treasury said in a statement.

The Treasury also announced it expects to borrow $847 billion in the third quarter, as it projects a cash balance of $850 billion at the end of September.

It also said in the first quarter the Treasury borrowed $748 billion in net marketable debt. It ended the first quarter with a cash balance of $775 billion.

The Treasury explained that the end-March cash balance was $12 billion below the January forecast because higher cash receipts and lower outlays were partially offset by a $25 billion higher ending cash balance.

(Reporting by Alden Bentley; Editing by Richard Chang)