Salomon’s Trading Chief Resigns Post : Wall Street: Dennis Keegan’s leaving marks the highest-level departure yet at the troubled investment bank.

The powerful head of trading at Salomon Bros. Inc. resigned Friday in the most senior-level departure yet to recently hit the defection-plagued investment bank.

In the unexpected shake-up, Salomon said it replaced Dennis J. Keegan, 42, with Shigeru Myojin, 45, a legendary Salomon bond trader who decided to forgo retirement to fill the opening as head of proprietary trading.

While top Salomon management was said to be disappointed with Keegan’s departure, they saw Myojin’s decision against retirement as a victory amid the recent defections, a source close to the firm said on condition of anonymity.

Myojin has been a high-flying Salomon bond trader based in Tokyo who in some years earned as much as half of Salomon Bros.’ total pretax profits. Earlier this year, he said he planned to retire in the fall.

Myojin, who was chairman of Salomon’s Asia unit, becomes Salomon’s vice chairman and will run proprietary trading, in which Salomon plays the markets with its own money for potential profit, out of London instead of New York.

Salomon Inc., parent of the Salomon Bros. investment bank, one of Wall Street’s biggest bond traders, has been shaken by huge losses and a controversial pay plan that triggered the resignations of some of its most talented investment bankers, traders and other staff.

The pay plan potentially would have sharply cut bonuses for top-earning professionals. But Salomon scrapped the plan earlier this month following the defections that included investment banking chief Richard J. Barrett and director of research Martin L. Leibowitz.

Salomon said through a spokesman that Keegan resigned for personal reasons, but the firm declined to elaborate. His employment plans were not clear and a telephone message left with his office was not returned. Observers said he was respected and liked by many of his co-workers.

Salomon apparently has begun to recuperate from a first-ever annual loss of $399 million last year. Profit rose 23% in the first quarter of 1995 as strong results in proprietary trading offset losses in investing services for clients.

“Dennis has made a very important contribution to our business, both in London and as head of proprietary trading,” Salomon Chairman and Chief Executive Deryck C. Maughan said in a brief statement.

Still, Salomon has come under pressure from stockholders for its unusually heavy reliance on proprietary trading, which has led to big losses as well as huge profits in the past. Salomon’s second-quarter earnings report is due out next month.

Salomon’s biggest stockholder is Berkshire Hathaway Inc., the Omaha firm largely owned by multibillionaire investor Warren Buffett.