Indian central bank says bought $11.9 bln in September

MUMBAI, Nov 13 (Reuters) - India's central bank bought a record $11.87 billion in intervention in September to slow the rupee's rise after U.S. rate cuts drew huge inflows into the stock market, its monthly bulletin showed on Tuesday.

The Reserve Bank of India has bought $51.8 billion in the first nine months of 2007, with the previous record purchase at $11.86 billion in February.

Despite the intervention the rupee has appreciated 12.3 percent against the dollar this year. It was trading at 39.4 rupees per dollar on Tuesday afternoon, after last week hitting 39.16 -- its strongest since March 1998.

Foreign portfolio flows of nearly $17 billion into the stock market this year have been a key driver for the rupee.

India's currency reserves have also risen $89.3 billion this year to $266.5 billion on Nov. 2. (Reporting by Anurag Joshi; Editing by Ranjit Gangadharan)