(Updates with comments on secondary offering, leverage) BERLIN, April 7 (Reuters) - Laboratory services group Synlab announced plans on Wednesday to float shares on the German stock market, offering investors exposure to the coronavirus testing boom and consolidation in Europe’s fragmented healthcare sector. Sources familiar with the matter have said that Synlab, backed by private equity group Cinven, could achieve a valuation of up to 6 billion euros ($7.1 billion) including debt when it lists in Frankfurt in the second quarter. Cinven bought Synlab for 1.7 billion euros in 2015 from BC Partners and merged it with France-based Labco, creating Europe’s largest lab services provider handling about 500 million tests a year for 100 million patients. Synlab said it aimed to raise 400 million euros from the offering of new shares from a capital increase, while current shareholders including Cinven, Novo Holdings and Ontario Teachers’ Pension Plan Board would sell down their stakes. The size of this secondary offering has yet to be determined. “We have delivered a remarkable growth story over the past years. The planned IPO is a consequent next step for us to realise our full potential as a publicly listed company,” said CEO Mathieu Floreani. A record run by German stocks is luring more companies to the stock market, with Vodafone’s Vantage Towers unit valued recently at 12 billion euros and used-car trading platform AUTO1 priced at 8 billion euros. Several further flotations are expected in Frankfurt before the summer break, including enterprise software company SUSE, online car dealership MeinAuto, as well as well as e-commerce firms About You and Mr. Spex. CONSOLIDATION PLAY Although European lab operators, providing standard blood and urine tests as well as other medical and veterinary diagnostics, have been consolidating to cut costs, the industry remains fragmented as reimbursement rules differ across the European Union. On the back of strong demand for Synlab’s COVID-19 testing capacities, the group said it had 2020 adjusted earnings before interest, tax, depreciation and amortisation (EBITDA) of 679 million euros, a 71% increase. Last year’s profit growth made it possible to roughly halve Synlab’s leverage ratio - measured as net debt to EBITDA - to 3.3 times at the end of last year, Chief Financial Officer Sami Badarani told a presentation. Synlab reported revenue of 2.6 billion euros last year and forecasts sales will exceed 3 billion euros in 2021. It projects 10% annual revenue growth over the longer term, of which 3% will be organic with the rest driven by acquisitions. The company this year completed a 550 million euro divestment of its analytics & services business, which is focused on environmental testing, to SGS, prompting a ratings upgrade by Fitch. According to Fitch, about a fifth of Synlab’s sales are COVID-19 related, a positive factor that the ratings agency expects will still be relevant until 2023, albeit likely on a smaller scale. ($1 = 0.8425 euros) (Additional reporting by Arno Schuetze, Editing by Thomas Escritt, Shailesh Kuber, Toby Chopra and Kim Coghill)