Mr McLeod handed in his resignation last month and is planning to leave the group by the end of the year.
Although he does not yet have another job lined up, he is considering a number of different "exciting" opportunities.
These are thought to include an offer from Colin Williams, a former BT executive and mentor of Mr McLeod's, who works for Level 3 Communications, an aggressive US group.
Level 3 has raised billions of dollars to build a world-wide telecom network based on packet-switching technology, which allows telephone calls to be parcelled up and transmitted over a network at high speed.
Mr McLeod's exit is the most prominent in a recent number of departures of UK staff from WorldCom.
WorldCom has grown at a break-neck pace, most recently through last year's merger with MCI, the US long-distance telecom group, which is due to receive final clearance in the next few weeks. Mr McLeod said his departure was amicable. "I've had the best three years of my career. I had a number of goals I wanted to achieve and I've done that." He dismissed as "complete and utter nonsense" suggestions that he had fallen out with Liam Strong, the former Sears chief executive who runs WorldCom's European operations.
Mr McLeod originally joined MFS, the telecom group which specialised in providing telecom connections to business users in London and other European cities, in 1995 after spending 12 years with BT.
After MFS was swallowed by WorldCom, he was put in charge of the UK division, which he expanded by establishing connections to the US and continental Europe while building up its UK customer base.
WorldCom recently announced the completion of its European network, which links the Continent's business centres. It is now planning to expand its network in the UK by buying spare capacity from other operators such as Racal Telecom.