In separate filings to the BSE, L&T said that Naik has sold 1.25 lakh shares for Rs 15.70 crore, while Venkataramanan sold 10,000 shares for Rs 1.26 crore.
Both transactions took place on March 14 and the company was informed the same day, the filing showed.
After the sale, Naik holds 23,17,455 shares of L&T of Rs 2 each, amounting to 0.25 per cent stake in the company.
Similarly, Venkataramanan now holds 8,42,873 shares of L&T, amounting to 0.091 per cent stake.
On March 10 and 11, Naik had sold 25,045 shares of L&T for Rs 3.12 crore in two tranches.
Shares of the company were trading at Rs 1240.10 apiece on the BSE at 1350 hours, down 1.23 per cent from the previous close.