CHEMICAL <CHL>, MARINE MIDLAND <MM> CUT PRIME Chemical Bank and Marine Midland Banks Inc said they are cutting their prime lending rate to 9-1/4 pct from 9-3/4 pct, reversing an increase that they announced just last week. The reduction is effective immediately. No other major U.S. bank had followed the lead of Chemical and Marine Midland, preferring to keep their prime rates at 9-1/4 pct while they waited to see what course money market rates would take. Following Monday's record fall in Wall Street stock prices, money market rates fell sharply on Tuesday as investors ploughed proceeds into short-term instruments and the Federal Reserve said it is prepared to provide liquidity to support the economy and the financial system. Eurodollar deposit rates in London fell by as much as 9/16 percentage point, Treasury bill rates fell by as much as half a point (after falling between 59 and 84 basis points on Monday), and the Fed funds rate dropped to 7-1/4 pct from Monday's average of 7.61 pct. Speculation even surfaced of a discount rate cut to calm the markets, dealers said.