Commerzbank AG declined to comment on whether it will accept Bosch's €29.15 per share offer for the bank's 10.53 per cent stake in Buderus AG.
"We will examine the offer and afterwards make our decision," a spokesman for the bank said.
Earlier today it was announced that Bosch will acquire Bilfinger Berger AG's 30.02 per cent stake in Buderus for €550 million, and that it will offer the same price per share to remaining shareholders.
Bosch, the privately-owned German car parts and industrial technology company, stepped up its long-running efforts to acquire Buderus this morning, when it launched a €1.8 billion ($1.9bn) takeover offer after raising its existing stake in the heating appliance maker to more than 47 per cent.
Bosch has been forced to abandon takeover bids for Buderus in the past after talks with shareholders failed. Today it said it would offer €29.15 per share to all Buderus shareholders, a 7.2 per cent premium on Friday's closing price.
The deal, which values Buderus at about €1.8 billion, would see Bosch become Europe's largest heating appliances company, ahead of privately-held Vaillant, the current leader.
Commerzbank is the last remaining major shareholder in the heater maker.
Deutsche Bank AG sold its 7.47 per cent stake to Bosch for €100 million last year.
German banks have sold a raft of industrial shareholdings recently tocompensate for weak earnings and high loan losses.
AFP