Quick approval by both houses of Congress is expected of compromise legislation, agreed to late Tuesday by a House-Senate conference committee after 24 hours of chaotic negotiations, that would limit liability against companies for Year 2000 (Y2K) computer failures. The White House, which was a part of the negotiations, indicated that President Clinton will sign the measure. The House-Senate deal over the long-stalled legislation elates the business community, which has made its enactment a top priority in the current session of Congress. "This is a huge victory that comes in the face of fierce opposition from trial lawyers," declares Thomas J. Donohue, president and CEO of the U.S. Chamber of Commerce, which co-chairs (with the National Assn. of Manufacturers) a business coalition that has lobbied for Y2K legislation. "The Y2K bill will allow businesses to put their money into fixing the problem rather than spending it on paying lawyers to deal with frivolous litigation." The compromise bill among other things caps punitive damages at $250,000 or three times the financial damages, whichever is greater, allows companies 90 days to fix any computer problems before they could be sued, sets up a "proportional liability" formula for assessing blame, and calls for class-action suits to be tried in federal courts if they involve at least $10 million in claims and 100 or more claimants.