SAN FRANCISCO — The struggling Internet company AOL plans to shed up to 2,500 jobs — more than a third of its work force — as it prepares to separate from Time Warner and finally sever their ill-fated marriage.

Major job cuts had been expected and seemed certain after Time Warner said last week that AOL would take $200 million in charges for severance and other restructuring-related costs. But the magnitude was not known until today.