BC Asia Growth Investments and BC Investments Vi, units of U.S.-based Bain, offloaded about 70 million shares for 130 rupees apiece, a marginal discount to L&T Finance's closing price on Monday.

Data from BSE India also showed that financial services firm BNP Paribas bought about 36.4 million shares in L&T Finance in a single block deal.

Shares of L&T Finance were down nearly 3% on Tuesday, the biggest drop in nearly three weeks. They were up about 45% so far this year.

There will be a 90-day lock-in period for Bain Capital from selling further stake in L&T Finance after the block deal, Indian broadcaster CNBC-TV18 reported earlier in the day, citing sources.

In July, Bain Capital had entered an agreement to acquire a 90% stake in billionaire Gautam Adani-owned Adani Capital and Adani Housing.

The private equity firm is also in talks to buy a 10% stake in snack food maker Haldiram's, Reuters reported last week.

(Reporting by Biplob Kumar Das in Bengaluru; Editing by Shinjini Ganguli)