Opener Cook, who has been woefully out of form with the bat, will be replaced as skipper by swashbuckling middle-order batsman Eoin Morgan.
Cook was at the helm when England lost 5-2 in Sri Lanka in this month's one-day series.
The Essex batsman has toiled all year in the 50-over format, hitting 523 runs in 20 matches at a mediocre average of 27.52
Morgan, however, has fared even worse with the bat in 2014, averaging 25.45.
But the Middlesex left-hander has an impressive record in the eight one-day matches in which he has captained England, piling up 427 runs at an average of 71.16
England will warm up for the World Cup by playing in a Tri-Series competition in Australia next month.
The World Cup starts on Feb. 14 and Morgan's men have been drawn in Pool A along with Australia, New Zealand, Sri Lanka, Afghanistan, Bangladesh and Scotland.
Image: Eoin Morgan
Photograph: Gareth Copley/Getty Images
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