MOSCOW (Reuters) - The AAR consortium, representing four Soviet-born tycoons, said it would receive $28 billion in cash for the sale of its one-half stake in TNK-BP <TNBP.MM> to Russian state oil firm Rosneft <ROSN.MM>.

"I can confirm that it's $28 billion in cash at closing," AAR CEO Stan Polovets told Reuters after the parties signed a sale and purchase agreement on Wednesday.

Rosneft has already signed a binding agreement to buy out BP's <BP.L> stake in TNK-BP, Russia's third largest oil firm, for $27 billion in cash and stock.

Both legs of the deal - Russia's largest takeover - are expected to close in the first half of next year, subject to regulatory approvals.

(Reporting by Douglas Busvine; Editing by Katya Golubkova)