NATION

Mellon Bank Corp., which underwent a management shake-up following the announcement of unexpected losses, said W. Keith Smith had been appointed treasurer of the nation’s 12th-largest bank holding company.

Chairman Frank V. Cahouet, the former Crocker National Bank executive who last month was named to replace J. David Barnes, announced that Smith would also serve as Mellon’s chief financial officer and as a vice chairman of the company and its bank unit. Smith succeeds G. Christian Lantzsch, who had held those posts since January, 1980, and who retired during the recent shake-up. Smith, 52, was executive vice president and chief financial officer of PACCAR Inc., a manufacturer of heavy duty trucks. He went to PACCAR from Crocker, where he served as executive vice president and chief financial officer during Cahouet’s tenure as chairman and CEO.