May 19 (Reuters) - Russia's Yandex has received bids from billionaires Vladimir Potanin and Vagit Alekperov for a stake of at least 51% in the company's local business, valuing it at about $7 billion to $7.5 billion, Bloomberg News reported on Friday. (Reporting by Mrinmay Dey in Bengaluru; Editing by Savio D'Souza)