Washington ? A bill that would produce the biggest change in federal bankruptcy laws in more than 25 years hit a snag Wednesday night just as it appeared to be about to pass.

Senate leaders decided to postpone until today the final vote on the measure, which would make it more difficult for individuals to wipe out debt through bankruptcy. The decision was prompted in part by an amendment proposed by Paul Sarbanes, D-Md., John Warner, R-Va., and Patrick Leahy, D-Vt., which would prohibit an investment bank that advises a company before it files for bankruptcy from continuing to advise it after the company is in bankruptcy.

If adopted, the legislation would require many people to repay some of their debt under Chapter 13 bankruptcy filings rather than erase it almost entirely under Chapter 7 of the U.S. bankruptcy code. It would impose a detailed formula under which bankruptcy judges would have little leeway in determining who is eligible for Chapter 7, keeping it out of the reach of 30,000 to 100,000 people who file for bankruptcy each year.

Consumer advocates and many Democrats say the bill would be too harsh on people who fall on hard times from sickness, divorce or job loss, and that it retains loopholes that allow rich people who file for bankruptcy to hide millions of dollars in mansions and complex trusts.