US capital markets ought to come to terms with the success of Aim, the London Stock Exchange's junior market, and stop "navel-gazing based on the dubious premise that the US is 'the home of capitalism'," Clara Furse, the LSE's chief executive, says in a letter published in the Financial Times today.

The letter comes shortly after a US Securities and Exchange Commissioner referred to Aim as a "casino" and said the LSE risked harming its reputation through its operation.