The U.S. Congress may have scope to extend debt-limitnegotiations for weeks past the mid-October date when TreasurySecretary Jacob J. Lew has said the nation will exhaust itsborrowing authority, according to analysts at Credit Suisse GroupAG and Jefferies LLC.

Lew urged lawmakers last week to raise the $16.7 trillionceiling by the middle of next month, and said if they don't theTreasury would be forced to use about $50 billion in cash to fundthe government. Wall Street firms are trying to pinpoint when theTreasury's money runs out: Jefferies predicts sufficient fundsthrough the end of October, while Credit Suisse sees enough cashuntil as late as mid-November.

A delay past Lew's timetable threatensto disrupt the world's deepest debt market by postponing orreducing Treasury auctions, according to Goldman Sachs Group Inc.Lew's estimate reflects his concern that lawmakers will repeatdelays two years ago that led to the first downgrade of the U.S.'scredit rating, analysts said.