The supermarket group, which bought wholesaler Booker for nearly 4 billion pounds in February, said on Tuesday Melissa Bethell would join as a non-executive director on Sept. 24.

Bethell is currently a partner at Atairos, an investment fund backed by Comcast NBC Universal, and a director of Exor, a listed holding company for the Agnelli family.

But she is best known is her previous role at Bain Capital, the private equity firm, where she was managing director for over 18 years. She remains a senior advisor.

Prior to joining Bain Capital, Bethell worked in the capital markets group at Goldman Sachs with a focus on media and technology.

"Her broad range of skills and experience will be of significant benefit to the board as we implement our strategy," said Tesco chairman John Allan.

Allan said in February the Booker purchase was not the start of a buying spree for Tesco.

However, in July Tesco did agree to form a global purchasing alliance with France's Carrefour.

That deal came in the wake of Sainsbury's agreeing in April a 7.3 billion pounds takeover of Walmart's Asda - a combination that could see the combined group overtake Tesco as UK market leader.

(Reporting by James Davey; editing by David Evans)