reuters canadian buyout firm onex corp said it would buy swiss packaging group sig combibloc group ag sign.ul for up to 3.57 billion euros 4.43 billion.an additional payment of up to 175 million euros will be payable based on the financial performance of sig in 2015 and 2016, the private equity firm said.the deal is expected to close in the first quarter of 2015, subject to regulatory approvals, onex said.reuters reported earlier this month that onex, canadas largest listed private equity firm, was leading the bidding for sig combibloc, citing sources.sig is based in neuhausen am rheinfall, switzerland, and has annual earnings before interest, tax, depreciation and amortisation ebitda of about 420 million euros.sig operates seven production facilities globally, based out of europe, south america and asia pacific. the company is owned by reynolds group holdings limited, backed by new zealands richest man, graeme hart.source httpca.reuters.comarticletopnewsidcakcn0j80eq20141124