WILHELMSHAVEN, Germany, Dec 17 (Reuters) - German natural gas trader Uniper expects the European Commission to decide in coming days on whether Germany's planned bailout of the company violates state aid rules, its chief executive said, adding that any approval was likely to be tied to conditions.

Berlin's rescue of Uniper, which has so far cost more than 50 billion euros ($53 billion) and will essentially lead to full nationalisation, won clearance from EU competition regulators on Friday but still requires state aid approval from the EU executive.

EU state aid rules aim to prevent one company being unfairly subsidised to the detriment of others in the sector and may lead to regulators seeking financial or other commitments from parties in a deal before granting approval.

Uniper's investors will vote on the bailout at a shareholder meeting on Dec. 19.

"We expect there to be conditions, that's normal in these cases," CEO Klaus-Dieter Maubach told Reuters on Saturday. "We hope that the requirements aren't too drastic ... We expect a decision in coming days."

Maubach, who was speaking after the inauguration of Germany's first floating liquid natural gas terminal, said producers would need long-term commitments to ensure sufficient supplies of the LNG on which Germany has pinned its hopes of ending its reliance on imported Russian gas.

"(Exploration) projects are secured with long-term contracts. That's at least 10 years, better yet 20 years," he said. "We have to accept that we need to go into long-term delivery contracts, like we had with Russia."

While the firm would certainly need to be restructured under public ownership, some strategic commitments would remain unchanged, including its ownership of three Swedish nuclear power stations that generate 1.4 GW of power.

"That is part of our portfolio," Maubach said. "A very successful part."

($1 = 0.9450 euros) (Writing by Thomas Escritt; Editing by David Holmes)