Feb 20 Reuters Raiffeisen Bank International39;s shares suffered their worst daily drop since the onset of the Ukraine war on Monday, after news that the Austrian lender has drawn the attention of U.S. sanctions officials over its Russian business.

Shares in the bank were down 7.6 at 1130 GMT after it told Reuters on Friday it had received a request for information from the U.S. Treasury Department39;s Office of Foreign Assets Control OFAC to clarify payments business and related processes maintained by RBI in light of the recent developments related to Russia and Ukraine.

Raiffeisen is deeply embedded in the Russian financial system and is one of the only two foreign banks on the Russian central bank39;s list of 13 systemically important credit institutions, underscoring its importance to Russia39;s economy, which is grappling with sweeping Western sanctions.

The bank told Reuters in a statement on Friday that it is cooperating fully with OFAC and that it understood the request was not triggered by a specific transaction or business. It said it had processes in place to ensure compliance with sanctions.

The U.S. Treasury can penalise firms that break sanctions, including freezing U.S. assets and excluding banks from accessing U.S. dollars, something that is critical for their involvement in international trade and finance.

BNP Paribas Exane analysts downgraded their Raiffeisen rating from outperform to neutral over the potential risks.

However, Erste Group analysts…