"The management of Wintershall Dea must review and, if necessary, implement all measures that may contribute to averting or mitigating damage to the company, its employees and shareholders," said a spokesperson for Wintersall DEA.

That included the possible use of guarantees, insurance and possible legal means, the spokesperson added.

After months of uncertainty, Wintershall Dea said this week it was pulling out of Russia, which accounts for about half its production. Its stakes there had been "effectively expropriated", it said.

As a result the company, in which BASF holds just under 73% percent, has to take a hit of more than 5.3 billion euros.

BASF said it would take a 7.3 billion euro writedown as Wintershall Dea pulled out of Russia.

Germany's economy ministry confirmed that Wintershall Dea can use state investment guarantees.

(Reporting by Patricia Weiss; Writing by Madeline Chambers; editing by Matthias Williams)