PARIS, May 26 (Reuters) - France’s Aramis Group, which specialises in selling second hand cars online, said on Wednesday its had taken a first step towards an initial public offering (IPO) in Paris this year following a boom in used vehicle sales and as it looks to grow across Europe. The firm - which is 70% owned by Stellantis , the carmaker formed by the merger of France’s PSA and Italian-American group Fiat Chrysler - said its registration document had been approved by the French financial markets authority (AMF). “(This) constitutes the first step of its contemplated IPO on the regulated market of Euronext Paris”, Aramis said. “The completion of the IPO is subject to the approval of the prospectus relating to the offering by the AMF, as well as favorable market conditions”, it added. Aramis also said Stellantis will maintain a majority ownership after the IPO. (Reporting by Benoit Van Overstraeten; Editing by Dominique Vidalon)