Sexton, who is also regional director of Modem Media Europe, leaves the firm's London office this week in a move he described as "entirely mutual".
"I've done this for six years and it's time for a change, said Sexton.
"The firm is doing well; I felt it was time to look around. The management is fine and I'm fine. My immediate plan is to spend time with my family."
Sexton said that Norm Johnston, director at Modem Media UK, would lead the firm while a replacement was found over the next few weeks.
He declined to comment on whether Modem Media's international office in the US was looking to fill his Modem Media Europe position.
In May, Modem Media revealed that revenues for its international operations, including London, Munich and Hong Kong, were $5m (£3.4m) for the three months ending 31 March 2002, down from $8m (£5.4m) in the equivalent period last year.
The firm's overall first-quarter revenues were $20m (£13.6m). At the time, the agency said it expected a turnover of between $80m and $90m (£54.5m and £61.3m) for the year.
Sexton joined Modem Media UK in 1998, after it merged with the European arm of digital agency Poppe Tyson Interactive, of which he was a founding director.
_1.jpg)
.jpg)
