MIAMI BEACH: Employers would be required to give workers at least 45 days notice for pension plan changes that could reduce their benefits, under a bill proposed by President Clinton July 14. "Too many workers are left in the dark when their pension plans change," Clinton said in a written statement while attending a fund-raiser held by Communications Workers of America. "Every worker deserves meaningful and timely information about changes to their retirement benefits." The proposal is aimed primarily at alerting workers to a new kind of pension program called a "cash balance" plan, which is increasingly popular among big firms such as Bell Atlantic, Bank of America, Chase Manhattan, and IBM. IBM said earlier this year it would save $200 million annually by switching its 141,000 U.S. employees to a cash-balance program, in which pension benefits accumulate uniformly each year rather than growing slowly at the start of a worker's employment and accelerating as retirement approaches.