Activist investor TCI demanded earlier on Wednesday that the exchange answers a series of questions on why Rolet is standing down.

"The letter calls on us to provide clarity to shareholders," the LSE said in a statement.

"The Board has a duty to present to shareholders in a Circular all the facts necessary, at the same time, for them to take a decision and  it will of course respect this duty."

The LSE must hold an extraordinary general meeting to vote on a proposal from TCI to remove its LSE Chairman Donald Brydon. TCI says Brydon has not explained why Rolet is leaving.

LSE said in October that Rolet would leave by the end of 2018.

(Reporting by Huw Jones)