The European Central Bank has given UniCredit the green light to buy up to 29.9% of Commerzbank , the Italian bank said on Friday, adding it would likely wait until next year before deciding whether to pursue a full takeover.

UniCredit SpA cleared an important hurdle for a potential takeover of Commerzbank on Friday, but it also raised fresh doubts whether the deal will actually ever happen.

Italian banking giant UniCredit said Friday it had secured approval from the European Central Bank to up its stake in Commerzbank, but warned there were still hurdles ahead before a possible takeover of its German rival.