Bankers are lining up around £500 million of debt to back a potential sale of Safety-Kleen Europe Limited as five buyout firms make it through to the final round of bidding for the company that provides used oil collection, recycling and parts cleaning services, banking sources said. APAX Capital, LLC, Ardian, HgCapital, Montague International Holding Ltd. (OTCPK:MIHL) and Onex Corporation (TSX:ONEX) have all made it through to the second round of bidding, which is due to take place on May 24, 2017, the sources said. APAX Capital, LLC and Ardian declined to comment, while the rest of the bidders and Warburg Pincus were not immediately available to comment.