Senate leaders are optimistic about forging an eleventh-hour deal preventing a possible federal default and ending the partial government shutdown.

It's just hours from Thursday, the day the Obama administration has warned it will run out of borrowing authority and face the risk of a federal default that could shake the world economy.

Aides to Senate Majority Leader Harry Reid and Minority Leader Mitch McConnell say the two men were negotiating and expressed optimism that they could conclude a deal reopening the government and preventing default.

The Senate leaders' talks were continuing Wednesday after an extraordinary day in the House. On Tuesday, House Speaker John Boehner produced two bills to end the shutdown and avoid a default but couldn't find enough GOP support to bring them up for votes.