Italy's UniCredit defied Germany's defence of Commerzbank by using derivative contracts on Monday to raise its potential stake in the German bank close to 21%, while waiting for regulatory approval to go above 9.

Italy’s UniCredit moved to buy another big chunk of Commerzbank, shrugging off German opposition to a possible takeover and upping the ante in its attempt to create a European banking champion with nearly $1.

Commerzbank AG dropped after Germany said it won’t sell any more shares in the lender, a move signaling its opposition to any takeover by Italian rival UniCredit SpA.