By Aimee Look and Joshua Kirby

UniCredit said it upped its stake in Commerzbank to nearly half, taking it close to majority control of the bank following a takeover push.

The Italian lender said Wednesday that it secured 17.6% of the bank's shares in a tender offer, taking its stake in Commerzbank to 47.6% when combined with its existing direct stake and another smaller stake to which it has economic rights.

UniCredit, Commerzbank's largest investor, in March launched an all-share offer that at the time valued the target at around 35 billion euros, but now values it at around 41.9 billion euros, based on UniCredit's share price Wednesday.

"The completion of the tender offer periods represents a further step in the execution of UniCredit's strategic investment in Commerzbank," UniCredit said.