CINCINNATI (AP) _ In a move to lower expenses, Gibson Greetings Inc. said today it will cut its workforce by 5 percent, eliminating about 128 jobs.

Gibson, a greeting card company, said it expected to save $5 million before taxes next year from the downsizing.

The Cincinnati-based company made headlines recently when it sued Bankers Trust New York Co. Inc. after losing millions on risky derivative contracts.

The job cuts are not related to the derivative losses, company officials said.

''Today's decision is intended to improve our overall productivity and competitiveness and to accelerate our objective of achieving higher returns and lower costs in our business,'' said Benjamin Sottile, Gibson's chairman.

''This action at our card division and at corporate headquarters, coupled with programs being instituted at our Cleo gift wrap subsidiary, should enable Gibson to generate substantially greater profitability in 1995,'' he said.

Gibson will spend $1.5 million on severance pay and other costs related to the layoffs. The expense will be charged against 1994 fourth quarter earnings, the company said.

Gibson recently settled the Bankers Trust suit, agreeing to pay the bank $6.18 million to get out of soured derivative contracts that would have cost the company at least $19 million. Gibson said the losses threatened the company's survival.

Derivatives are customized securities whose values are based on, or derived from, an underlying market such as stock prices or interest rates.

William Flaherty, Gibson's vice president for finance, said the layoffs were made strictly for economy of operation.

''They have no relation to the derivatives losses,'' Flaherty said.