AMERICAN EXPRESS CO. (New York) - Takashi Hosomi was named a special adviser to James D. Robinson III, chairman and chief executive.

Mr. Hosomi is a former Japanese vice minister of finance and serves as adviser to the president of Nippon Life Insurance Co.BANK OF MONTREAL (Toronto) - A. Donald C. Mutch was named president of the newly formed Bank of Montreal Investment Management Ltd.

He was deputy treasurer of the bank.

KIDDER, PEABODY & CO. (New York) - Marshall V. Davidson was named a managing director and co-director of the firm's financial services group. He was a managing director and head of investment banking for commercial banking companies at Drexel Burnham Lambert.

Joining him in the move from Drexel are David Taylor Maughan, who will be named a managing director; and George A. Bicher III, who will be a vice president. Also making the move are Matthew Lindland, associate, and Sergio Vladimirischi, associate intern.

NCNB CORP. (Charlotte, N.C.) - Brad C. Iversen was named consumer marketing division executive.

He was a senior vice president for MasterCard International in charge of the company's strategic planning.

NORWEST CORP. (Minneapolis) - Michael W. Krutsch was named vice president and manager of the Denver office.

He was vice president of the consumer products division of corporate banking for Norwest Bank Minnesota, based in St. Paul.