US aerospace giant Boeing and Sberbank of Russia announced Thursday that the top Russian bank has agreed to buy 12 Boeing 737 aircraft for leasing. The deal is valued at more than $1 billion at current list prices, the companies said in a joint statement. The bank\'s Sberbank Leasing unit will lease the dozen Next-Generation 737-800 planes to Transaero, one of the bank\'s key corporate customers. Through the accord, the companies hope to lay the groundwork for developing an environment for finance and operational leasing of imported aircraft in Russia. \"The agreement that we have reached today marks a very significant step forward and is evidence of Sberbank\'s commitment to aviation financing,\" Sberbank chairman and chief executive Herman Gref said. \"It substantially contributes to the development of trade and economic relations between Russia and the US.\" Shep Hill, president of Boeing International, said the US firm was \"privileged to enjoy the support and confidence of Sberbank as the bank moves into aircraft leasing.\" The Boeing 737-800, a version of the Next-Generation 737 family, can seat between 162 to 189 passengers. The single-aisle Boeing 737 is the best-selling jetliner in aviation history.