FRANKFURT, Feb 25 (Reuters) - German generic drugs maker Stada Arzneimittel said on Saturday it had started a structured bidding process after receiving takeover bids from three buyout groups.
"For this purpose, a data room has been established and the potential bidders - three to date - have been invited to conduct multi-stage due diligence," Stada said in a statement.
Stada has become the subject of a three-way bidding war between Advent, Cinven and a third buyout group that sources identified as Bain Capital.
Due diligence gives potential buyers access to the target's books and data.
Activist investor AOC, Stada's biggest investor with a stake of more than 5 percent, a called a day earlier for the company's management and supervisory boards to run a non-biased, transparent sales process.
(Reporting by Christoph Steitz; editing by David Clarke)