Tim Price, chief executive for the company's communications group, plans to leave the company in February, according to a statement from the Clinton, Miss.-based company.
Price headed MCI WorldCom's largest operating group, overseeing the company's telephone strategy as well as its successful UUNet Internet division.
The departure comes at a critical time for MCI WorldCom, which recently agreed towith rival Sprint in the largest corporate marriage of its kind to date. That merger has yet to be approved by federal regulators.
Price is the latest in a series of top executives who have left following the merger of MCI and WorldCom. Price came to the merged company from MCI, where he had been president of that firm's communications division.
"He made a promise to employees and shareholders to stick around until the merger had been completed," said Brad Burns, an MCI WorldCom spokesman. "He feels like he's done that."
Analysts have widely predicted that Sprint CEO William Esrey would similarly cut his ties after the completion of the Sprint-MCI WorldCom merger.
The company did not make public any reasons for Price's departure, or indicate what the executive's future plans might be.
Analysts downplayed the news, saying that Price was valuable but not critical to the company's strategy.
"It's not like they're losing Bernie Ebbers," said Leslie Stonestreet, a telecommunications analyst for Banc of America Securities. "It's a surprise. But I'm not too concerned about it."
"My decision to leave MCI WorldCom has been enormously difficult," Price said in a short company statement. "It has been a privilege and pleasure to work with Bernie [Ebbers]. He is a legend in American business, a superb leader, and a good friend."