The prime lending rate remained at 6.75 per cent today despite speculation that it might have climbed another quarter-point.

Citibank, the nation's second largest, which kicked off the step-up to 6.75 per cent May 27 and to 6.5 per cent two weeks before, said it wouldn't take the next step to 7 per cent.

On Wednesday, President Carter's budget director, Bert Lance, criticized bankers for raising the rates they charge on lonas to their best corporate customers.

Lance charged the increases were fueling inflation and said his "concern rates" even though "loan demand just isn't there."

Some bankers disputed Lance's claim, however, saying their money costs are steadily rising and that their outlook for loan demand now appears to be uneven rather than down.

A boost in the prime rate was expected after the release of Federal Reserve figures Thursday which showed the price of commercial paper - unsecured loans by corporations - was nearing 5.50 per cent.

A formula used by Citibank to help determine its prime rate pegs the rate at 1.5 points above that for commercial paper. In addition, the price of Treasury bills and of the banks' own certificates of deposit has been rising steadily in recent weeks.

But a Citibank spokesman said after applying its formula, the anticipated prime rate still was a shade under 7 per cent. "It was a marginal thing," he said."We've done this before."

He would not comment when asked if Lance's comments had influenced the bank's decision.