Indiabulls Real Estate (IBREL) today announced sale of its office project in Chennai to global investor Blackstone for Rs 850 crore as part of its strategy to monetise commercial asset. The company had in March this year sold 50 per cent stake in two prime commercial properties in Mumbai to Blackstone for Rs 4,750 crore. In a filing to BSE, IBREL informed that a committee, constituted by the board, has authorised execution of definitive transaction documents with Blackstone group firms for divestment of its 100 per cent stake in its commercial assets at Ambattur, Chennai.