But the bank also said the deal for the Strabag stake, which has faced scrutiny by U.S. government officials, "requires extensive compliance verifications" following a recent transfer of the holding.

The disclosure by Raiffeisen (RBI) on Tuesday is the latest development in its attempt to unlock the stake in a complex deal as a means of freeing up some of its billions stranded in Russia. Reuters reported on March 20 that U.S. Treasury officials have expressed their concerns about the transaction in meetings with the bank and Austrian authorities.

In December, RBI announced it intended to buy the 1.5 billion euro Strabag stake from Russia-based Rasperia Trading Limited, a company controlled by sanctioned Russian businessman Oleg Deripaska.

Around the same time, Strabag said Iliadis JSC was buying Rasperia, a deal whose conclusion was announced last week.

Russian company filings as of last week showed that Iliadis was registered as a company on July 12, 2023, but its ownership is unclear.

"While this recent transaction is unrelated to RBI's announced acquisition of the STRABAG SE shares, it requires extensive compliance verifications," RBI said.

It said Rasperia's new ownership structure needed to give RBI "comfort that no sanctioned individuals or entities will benefit directly or indirectly" by its Strabag deal.

RBI had initially said it planned to close its deal by the end of March.

(Reporting by Alexandra Schwarz-Goerlich; writing by Tom Sims; Editing by Jan Harvey and Bill Berkrot)