The Senate yesterday quickly followed the House's lead and voted to raise the lending authority of the Export-Import Bank, which has virtually run out of money to finance American foreign trade. But the Senate approved a different figure, which means that the bills must go to conference to settle differences or that the House must accept the Senate change.

The House had approved an increase of $251 million in direct loans and $274.7 million in loan guarantees for the fiscal year that ends Sept. 30. The Senate Approved a total of $1.25 billion in direct loans, but only $251 million would be available immediately. The rest could not be obligated or disbursed before Oct. 1.

The Ex-Im Bank, which plays a crucial role in U.S. trade, is in financial trouble because it got caught in a fight over foreign aid. The bank is funded by a provision in the foreign aid appropriation bill, which was not enacted this year, and is kept going by stopgap spending authority. An attempt to increase the bank's funding in a supplemental appropriation bill last month failed on the last night before the Fourth of July recess when the bank's money was thrown out to keep spending under the budget ceiling.