First Chicago Corp. said it added $240...

First Chicago Corp. said it added $240 million to the money it has set aside against losses on loans to developing countries and would have a fourth-quarter loss of $96.5 million . . . Beverly Hills-based American Medical International Inc. announced that it is restructuring its United Kingdom operations under a new holding company named AMI Healthcare Group and is considering a public offering of a minority percentage of the shares . . . United Airlines and Presidential Airways announced that they have entered into a marketing agreement that will allow Presidential to become a United Express carrier . . . American Airlines flight attendants have ratified a new contract eliminating a two-tier wage scale . . . The Federal Reserve said the average yield for one-year Treasury bills, the most popular index for making changes in adjustable rate home mortgages, edged down to 7.12% last week from 7.15% the week before . . . Parisian Inc. said P.I. Acquisition Corp., which is controlled by Hooker Corp. of Australia and major Parisian stockholders, is revising its bid to acquire Parisian to $30.65 a share from $33.65.