AMERICAN EXPRESS <AXP> UP ON SHEARSON RUMORS American Express Co climbed 2-1/2 to 80-1/8 on rumors the company was about to announce an agreement to sell 10 pct of its Shearson Lehman Brothers unit to Nippon bLife Insurance of Japan, traders said. Speculation about an impending deal, rumored to be worth 600 mln dlrs, also sent shares of other U.S. brokerages up sharply. PaineWebber Group Inc <PWJ> gained 1-5/8 to 37-1/8 and Merrill Lynch and Co Inc <MER> rose 1-3/8 to 42-7/8. American Express officials declined comment but cited a statement it released more than two weeks ago in which it said it was studying matters of strategic importance. American Express officials also pointed out the earlier statement, issued March one, said it is company policy not to comment on rumors or speculation. The earlier announcement also said American Express and Shearson were studying options including expansion of capacity to meet international competition and broadening access to capital. The latest rumors originated in Tokyo, traders said. If the rumors are true "it gives them a nice infusion of capital for an attractive price," said Lawrence Eckenfelder, analyst at Prudential-Bache Securities.