Cornwall (Luxembourg) S.a.r.l., a fund backed by U.S. activist investor Elliott which filed the motion to appoint a special auditor, agreed to the delay, one of its representatives told Uniper's annual general meeting, where shareholders had been due to vote on the motion.

Actively working to obstruct E.ON's $4.5 billion sale of the stake to Fortum would be a breach of management's duties which is not permitted under German takeover regulations.

The appointment of a special auditor would give Elliott, which owns 8 percent of Uniper, a lever to press for changes in the company's senior management, which is set to remain in place after the deal with Fortum.Representing shares held by Elliott-backed funds, Wolfgang Sturm of law firm Broich said the funds were prepared to delay the vote and give management an opportunity to prove they did not actively try to obstruct the transaction.

E.ON's proposal to delay the vote effectively leaves a decision on the appointment of a special auditor in the hands of future owner Fortum.

It comes just weeks before Fortum is expected to secure regulatory approval for its planned purchase of the 47 percent stake in Uniper from E.ON.

Russian authorities ruled in late April that Fortum cannot buy more than 50 percent of Uniper, dealing a blow to hedge funds that have bought stakes in hopes that the Finnish group could launch a higher follow-up bid later.

At the time, Fortum alleged that Uniper - an energy generation and trading company spun off from E.ON in 2016 - had worked to block the transaction in Russia, where Uniper operates power plants and water-testing through its local unit Unipro.

OPPOSED

Uniper's management has opposed the deal with Fortum from the start, arguing that the combination makes no strategic sense and fearing that Fortum might want to break up the group, but it has denied any wrongdoing.

E.ON's general counsel Guntram Wuerzberg, speaking on behalf of the group, also asked shareholders on Wednesday to delay a standard decision to endorse Uniper's management until the next general meeting, when Fortum will be the largest shareholder.

He said it was "too early" to vote on the motions, as approval for the planned transaction from Russian and European authorities was still outstanding. Sources had told Reuters on Tuesday that E.ON would seek to delay the decisions.

Uniper Chief Executive Klaus Schaefer said he would defend the energy group's independence, suggesting a full takeover of the group would not be possible with him in the driving seat.

He said that Uniper would still work to create a constructive working relationship with Fortum, which is controlled by the Finnish state and has denied it wants to break up Uniper should it gain full control.

"I'd like to state clearly that this wouldn't in any way alter our intention to remain an independent company. For the simple reason that it's the best foreseeable course for your company," Schaefer told the annual meeting.

(Editing by Susan Fenton and Adrian Croft)

By Christoph Steitz and Matthias Inverardi