EBay has compiled a shortlist of agencies and is believed to be considering PHD, Starcom Motive and Mediaedge: cia as well as MediaCom.
Ogilvy & Mather, Joshua, DFGW and Delaney Lund Knox Warren are battling for eBay's £3m creative advertising business, with a decision due imminently.
The reviews are a precursor to the launch of eBay's long-expected foray into above-the-line advertising.
Promotional activity in the UK has previously been confined to online and eBay has never had a UK creative agency. But it is now keen to become a global brand.
Former Unilever interactive marketing chief Simon Darling was appointed eBay group marketing director last year and is overseeing both reviews.
He replaced commercial director Linda Campbell, who is on a two-year sabbatical in the US.
EBay recently signed up as sole content provider on Freeserve's Auctions Channel.