Mark Weldon is stepping down as chief executive of NZX Ltd, the operator of the New Zealand stock exchange.

NZX has just announced that Weldon told the board he will step down as chief executive in the first half of next year, after nearly ten years in the job.

Mark has effectively been founder, as well as leader, of NZX, as we now know it, since 2002. Under his stewardship, NZX has grown from a small and threatened mutual exchange to a thriving information, markets and infrastructure business, with a range of integrated business lines, a healthy balance sheet and a valuable set of options for future growth, said NZX Chairman Andrew Harmos.

Following the successful execution of NZXs second five-year strategic plan, Mark has indicated that the time is now right for him to leave the company. The Board respects his decision.''

Harmos said that during the period of Mark's leadership the organisation had grown from a 2002 position of revenues of $10.4 million, a loss of $500,000, no dividends and a valuation conducted at $15 million, to its current position of operating profit approaching $30 million, dividends in 2011 of $17.24 million and a market capitalisation of around $288 million.

He said that by the eighth anniversary of its listing, NZX had generated a total return to shareholders of 535 per cent, or 24 per cent per annum.

Given the strength of the organisation and the wind that is now at our backs, I believe this is very close to an optimal time for both the individual and the organisation, said Harmos.

In the statement Weldon said, I have been privileged to have the opportunity to lead NZX throughout this time, working with wonderful, talented and passionate people who care deeply about our markets and the companies that depend on them to grow. Although its been a very tough decision to leave, I know its the right time. The organisation is in such good shape, with momentum building that will provide a positive working environment for the next CEO.

The statement does not say what Weldon is going to do after stepping down.