The London Stock Exchange has launched a vigorous defence of its business in the wake of "unfounded rumours".

The Exchange said it was a "thriving" business and defended the record of its chief executive, Clara Furse, who took over at the helm in February 2001, becoming the first female chief executive in its 200-year history.

In a statement, the group said: "The Exchange is aware of a number of unfounded rumours circulating in the market, some of them libellous and deeply offensive, which appear designed to undermine its business and reputation."

A report in the Financial Mail on Sunday said rumours were being spread to undermine Ms Furse.

The LSE yesterday said: "The Exchange under Clara Furse's leadership is light years ahead of where it was just a few years ago.

"The Exchange is thriving, its governance is sound and, most importantly, there are effective working relationships at board, chairman and senior executive level based on high professional and personal standards and trust.

"Over the past two years, Clara has delivered a well-thought-through and well-executed strategy to widen the scope and scale of the business."

It said this included heavy investment in its electronic trading platform, creating an equity derivatives business, buying Proquote, a market data services company, and launching a covered warrants market.

The statement said: "This and the Exchange's fine financial performance are a credit to Clara and the whole executive team."

Ms Furse, who is a Canadian-born Dutch woman, took over at the helm of the LSE following a year of turmoil at the Exchange.

She filled a seat which had been vacant for four months after Gavin Casey resigned following shareholder anger at the group's annual meeting.

Ms Furse had to deal with the knock-on effects from the LSE abandoning a merger with Germany's Deutsche Borse in order to fight off a hostile bid from Sweden's OM.

However, she has received some criticism for losing the battle for London derivatives exchange Liffe to Paris-based Euronext.