BENGALURU, Oct 8 (Reuters) - Indian shares extended gains on Friday after the central bank kept key interest rates unchanged as expected and promised adequate liquidity to support the economic recovery.

At 0525 GMT, the NSE Nifty 50 index was up 0.72% at 17,918.90 and the benchmark S&P BSE Sensex rose 0.80% to 60,126.87.

"There should not be any concern about the adequacy of liquidity in the banking system to support recovery or financial markets," Reserve Bank of India Governor Shaktikanta Das said in his policy address.

"Our entire approach is of gradualism, we don't want suddenness or surprises," he said, adding there was no need for conducting more G-SAP or government securities acquisition programme auctions at this point.

The central bank left the key lending rate or the repo rate steady at 4%, while the reverse repo rate or the borrowing rate also stayed unchanged at 3.35%.

Some analysts had signalled a slim chance of the monetary policy committee delivering a token increase in the reverse repo rate.

The country's benchmark 10-year bond yield hit a 17-month high of 6.30% after the decision, while the Indian rupee strengthened and broke the 75 mark, trading at 74.96 against the dollar after the RBI halted G-SAP purchases.

"It looks like a balanced policy from an equity market standpoint. While the RBI sees no immediate need for G-SAP, sticking to an accommodative stance suggests only a gradual removal of excess liquidity, and enough to support the recovery," said Abhiram Eleswarapu, head of India Equities, BNP Paribas.

"The market may have expected that a slight increase in the headline rates, which hasn't happened. So from that perspective, it's a marginally positive policy for the equity market."

Meanwhile, shares of Tata Consultancy Services were up 1.9% ahead of its September quarter results. The IT behemoth kick starts the earnings season and is being closely tracked for signs of recovery for India Inc. (Reporting by Nallur Sethuraman in Bengaluru; additional reporting by Savio Shetty in Mumbai; Editing by Sriraj Kalluvila)