The £2.4bn ($4.2bn) bid approach for the London Stock Exchange by US rival Nasdaq has given private equity a supporting role in the reshaping of the world's stock markets. US private equity groups Hellman & Friedman and Silver Lake Partners have been linked to the latest 950p-a-share suggestion, which was rejected by the UK stock exchange.

But observers question whether the latest development leaves a role for private equity, particularly if a successful bidder has to pay a higher price for the exchange.