OAO Sberbank (SBRCY) slid the most in a week in U.S. trading after the lender spent $3.5 billion to buy Denizbank AS (DENIZ) from Belgium’s Dexia SA. (DEXB)

American depositary receipts of Sberbank fell 1.6 percent at 12:29 p.m. in New York, tumbling the most since June 1. The stock was the second-biggest decliner on the Bloomberg Russia-US Equity Index (RUS14BN) of Russian U.S.-listed companies.

Sberbank, the biggest lender in eastern Europe, and Dexia signed the sale agreement today in Istanbul, where Denizbank is based, Dexia said in a filing with the Istanbul Stock Exchange. The sale is expected to be completed in the fourth quarter after regulatory approvals and the price may increase to as much as 7.09 billion liras, or 3.09 billion euros ($3.85 billion) at an exchange rate of 2.293, depending on changes to asset value, it said.

“Although positive in the long term, the purchase reduces return on equity in the short term, pushing the stock down,” Rinat Kirdan, analyst at Aton LLC in Moscow, said by phone.

Sberbank fell 2.5 percent to 81.33 rubles, or $2.50, also the lowest level since June 1, on Moscow’s Micex Index today.

To contact the reporters on this story: Halia Pavliva in New York at hpavliva@bloomberg.net

To contact the editor responsible for this story: Tal Barak Harif at tbarak@bloomberg.net