The duties of Chisholm, who resigned late last year, including team management and overseeing internal communications, have now been dispersed among the remaining members of the team.
The decision not to replace her follows a similar move after the departure of chief communications officer Matt Peacock to join third generation mobile operator Hutchison 3G as its director of external relations, last autumn (PRWeek, 13 September).
The most senior PRO at AOL is now head of media Jonathan Lambeth, who takes over full management of the two-strong corporate communications team of corporate comms managers Joss Cole and Vicky Prior.
Lambeth and Chisholm had jointly taken over Peacock's responsibilities following his departure.
Last month AOL, which is part of AOL Time Warner, announced that globally it expected to see revenues fall by around a half in 2003 due to the slump in the advertising sector.
This week AOL Time Warner chairman Steve Case announced he would be standing down in May, following reported pressure from shareholders. Since AOL's merger with Time Warner in 2001 shares have slumped by almost 70 per cent.