MORE U.S. BANKS JOIN IN PRIME RATE CUT
  Chemical Bank, the main bank subsidiary
  of Chemical New York Corp, and Marine Midland Banks Inc said
  they were raising the prime lending rate to 7-3/4 pct from
  7-1/2 pct, effective immediately.
      In St Louis, Mercantile Bancorp said its Mercantile Bank
  N.A. was also raising its prime rate to 7-3/4 pct from 7-1/2
  pct, effective immediately.
      The changes follow similar cuts yesterday by Citicorp and
  Chase Manhattan.
  

