UPDATE 1-Infosys CEO Vishal Sikka resigns; co names interim chief executive

(Adds background on boardroom tussle, share price move)

Aug 18 (Reuters) - India's No. 2 IT Services company Infosys Ltd said Vishal Sikka had resigned as managing director and chief executive of the company with immediate effect, sending shares tumbling more than 7 percent in early trading on Friday.

The move comes after a protracted war of words between the company and its founders and some former executives, who were unhappy with various decisions taken by the board.

The founders, who still own 12.75 percent of the firm, had questioned a pay rise granted to Sikka and the size of severance payouts given to others, including its former finance head Rajiv Bansal.

Infosys said U.B. Pravin Rao, its chief operating officer, had been named as interim managing director and chief executive. Sikka was named executive vice-chairman. 1/8http://bit.ly/2v6GW6I 3/8

Infosys shares fell 7.1 percent to a more than one-month low of 948.25 rupees at 0945 IST (0415 GMT). (Reporting by Euan Rocha in Mumbai and Tanvi Mehta in Bengaluru; Editing by Himani Sarkar)