Tait, the former American Express digital acquisition chief, was appointed as the group head of ecommerce at Arcadia in April.
A spokeswoman for Arcadia confirmed Tait had ''decided the role is not for him" and "left the business to pursue other interests". She declined to comment on the review, which sources said was linked to the group's ecommerce business.
Arcadia is understood to work with various specialist agencies on ecommerce around the world. The review is thought to be multi-market, and to primarily include search, with elements of affiliate marketing and digital display advertising.
The review will not affect Maxus, which works on media planning and buying for Arcadia in the UK, or Joint, which picked up the BHS ad account last month.