BlackRock, the world's biggest asset manager, said in a statement on Monday the move by China's State Administrator of Foreign Exchange would take the Qualified Foreign Institutional Investor (QFII) quota available to it to $1.25 billion.

The quota boost for BlackRock comes at a time when China's stock market has seen a wave of unprecedented selling, which has resulted in the government stepping in to revive investor confidence.

China has allowed foreign investors to tap its largely closed stock and bond markets through QFII and Renminbi Qualified Foreign Institutional Investor schemes (RQFII).

The $1.25 billion quote that BlackRock has is separate from the $640 million under RQFII, BlackRock said.

(Reporting by Denny Thomas; Editing by Christopher Cushing)