Clifford Chance (CC) and Simpson Thacher & Bartlett are advising on car marketplace operator Auto Trader's plans to undertake one of the largest initial public offerings (IPO) so far this year.

The float on the London Stock Exchange is expected later this month and could value the company at up to £2.5bn, according to reports.

In a statement Auto Trader Group said that the cash from the IPO would be used to "raise the profile of the group and provide an appropriate capital structure for future growth".

CC partners Adrian Cartwright and John Connolly are advising the underwriters, with Bank of America Merrill Lynch and Deutsche Bank acting as joint global coordinators and joint bookrunners for the listing.

Immediately following admission, Auto Trader expects to have a free float of at least 25% of the issued share capital of the company.

Should the float be successful, it would be one of the largest this year.

Simpson Thacher is advising Auto Trader. The firm was also called in earlier this year when Guardian Media Group sold its 50.1% stake in Auto Trader owner Trader Media Group to private equity house Apax, which was advised by Freshfields Bruckhaus Deringer.

Before deciding to go ahead with the IPO, Apax had considered selling Auto Trader to US private equity firm Hellman & Friedman.

Other sizeable IPO mandates in 2015 have gone to Latham & Watkins, which advised low-cost Hungarian airline Wizz Air; Davis Polk & Wardwell, which advised on Vision Express owner GrandVision's float along with Linklaters and Dutch firm De Brauw Blackstone Westbroek; and Freshfields, which acted on furniture retailer DFS's London listing.