Nov 24 (Reuters) - Monro Inc, an operator of U.S. car service and tire centers, is under pressure from an activist investor to improve returns and change operations, people familiar with the matter said on Tuesday.

Hedge fund Ides Capital has reached out to Monro's board and followed up with letters, urging the company to make changes that also include environmental, social and governance (ESG) improvements like diversifying its workforce and boardroom, according to the sources.

Monro's lack of diversity, especially in the boardroom, and broader ESG issues have held the company, valued at $1.5 billion, back, the hedge fund argued, according to the sources.

As recently as last month the hedge fund again expressed its concerns to Monro's board about performance.

Ides declined to comment and Monro did not immediately respond to requests for comment on Tuesday. (Reporting by Svea Herbst-Bayliss in Boston Editing by Matthew Lewis)