Carlyle, which owned about 5.2 percent of HDFC before Wednesday's block deals, sold about 20 million shares, raising about $270 million, at an average price of 677.25 rupees apiece, one of the sources said.

The price is at a discount of nearly 3 percent to HDFC's Tuesday close price of 697.85 rupees. The sale represents 1.3 percent of the Indian lender's outstanding shares.

Deutsche Bank was the sole manager to the transaction, said the source.

Shares in HDFC, which has a market value of $20.8 billion, were trading down 2 percent at 684.15 rupees at 11.58 a.m. (0628 GMT), while the main Mumbai market was down 0.3 percent.

Domestic as well as foreign investors bought shares sold by Carlyle, HDFC Chief Executive Keki Mistry told Reuters, citing market sources.

Most of the buyers were long-only funds. Aberdeen Asset Management is one among the buyers, who bought a significant chunk, the source said.

This is the first exit from the Indian market by Carlyle Asia Partners, the group's buyout fund.

At the current price, Carlyle has nearly doubled the return on its 2007 investment, one of the sources said.

Before the block deal on Wednesday, Carlyle was the No. 2 strategic investor in HDFC after Citigroup, which owns 8.8 percent of the mortgage lender.

In June last year Citigroup sold a 1.5 percent holding in HDFC. The sale was done ahead of the adoption of a global accord on banking that discourages large holdings by banks in other financial institutions.

Carlyle last month sold 18 million shares in China Pacific Insurance (Group) Co Ltd (CPIC), taking its holding below 5 percent.

Founded in 1987, the buyout giant manages $148 billion across 89 funds and 52 fund of fund vehicles.