BERLIN (Reuters) -Qatar is in talks with the German government over possibly buying Russian energy group Rosneft’s stake in Germany’s PCK Schwedt refinery, which Berlin placed under trusteeship following Russia’s invasion of Ukraine, the Business Insider news website reported on Wednesday.

The German government confirmed that there had been regular exchanges with Qatar regarding investment opportunities over the past three months, without specifying whether a potential purchase of Rosneft assets was among the talking points.

Joerg Kukies, state secretary in the German chancellery, has held discussions with Mansoor Ebrahim Al-Mahmoud, CEO of the Qatar Investment Authority (QIA), four times over the past three months, most recently on Aug. 14, the government said.

The QIA and Qatar’s international media office did not have an immediate comment. Rosneft did not immediately reply to a request for comment.

Berlin put Rosneft’s German assets under a trusteeship in 2022, while still conceding some control to the Russian group over a sale of the assets. A Rosneft lawsuit to challenge Berlin’s grasp over the assets failed in court last year. The current trusteeship term is set to expire on Sept. 10.

The German economy ministry told Reuters it would “make a timely decision” on further steps by then.

Relations between Russia and the West collapsed after the full scale invasion of Ukraine in February 2022 and Germany has taken steps to shore up its energy security after concluding it had previously relied too heavily on Moscow.

Rosneft has a 54.17% stake in PCK Schwedt, which has traditionally supplied 90% of the fuel used in Germany’s capital, Berlin.

In March, the German government said Rosneft had started the sale of its German assets and wanted to conclude the process by September.

Russian media has put the value of Rosneft’s assets in Germany at around $7 billion.

The refinery is also co-owned by Shell and Eni. In December, Shell announced the sale of its 37.5% stake in the refinery to Britain’s Prax Group.

(Reporting by Riham Alkousaa, Miranda Murray and Andreas Rinke; Additional reporting by Andrew Mills, Vladimir Soldatkin and Christoph Steitz; Editing by Rachel More and Ludwig Burger)