Advent International has laid down a marker in the three-way race to acquire German pharmaceuticals company Stada with a binding €3.6bn offer for the company.

The cash offer of €58 per share represents a 66 per cent premium on the company’s stock price at the end of March 2016, before news broke that activist investors were buying up shares in the business. The offer is higher than its original €55 per share bid.

Stada has now converted its talks with potential buyers into a formal bidding process. “The transparent and fair process which is open to further interested parties ensures that all potential bidders receive the same level of information and will have the same opportunity to present their plans for Stada,” the business said in a statement. Stada has set up a data room and potential bidders have been invited to conduct due diligence.

As well as Advent, Cinven and an unnamed third bidder — believed to be Bain Capital — have shown interest in acquiring the Frankfurt-based generic drug manufacturer, making offers of €56 a share and €58 a share respectively. The business sells into more than 30 countries and posted sales of €2.12bn in 2015.

In a statement Advent said its offer was legally binding, fully financed and offered “high transaction security”. The buyout firm added that is expected a deal to close after a dividend payment for the 2016 financial year, allowing investors to benefit from an anticipated dividend as well as the cash offer price.

Advent wants to expand Stada’s product lines, support bolt-on acquisitions and grow in new markets such as Asia and Latin America.

The offer is on the table until Monday and is subject to the Stada board’s blessing. The board said in a statement that it would review the offer and continue to hold “open-minded talks with all interested parties”.

The bidding war for the company comes after activist investor Active Ownership Capital built up a stake in the company a year ago, when its shares were trading at just €30 a piece.

Active was pushing for a management overhaul and since its investment long-serving chief executive Hartmut Retzlaff has stepped down and Carl Oetker has replaced non-executive chairman Martin Abend.