* Bristol Myers to focus on high-margin prescription drugs (Adds context, details on valuation): FRANKFURT/LONDON (Reuters) - German drugmaker Stada (STAGn.DE) and Italian healthcare company Angelini are the only industry players to be shortlisted to make final bids for Bristol-Myers Squibb’s (BMY.N) French over-the-counter drugs business, four sources close to the deal said. Two private equity firms, CVC Capital Partners and PAI Partners, have also made it through to the final round of the auction for UPSA, the maker of Dafalgan and Efferalgan painkillers, the sources told Reuters.