John Thain, the chief executive of the New York Stock Exchange (NYSE), risked raising tensions between London and New York yesterday when he voiced concern over Russian corporate governance and criticised bourses for courting international listings of former Soviet Union groups.

Less than a month after a commissioner of the US Securities and Exchange Commission (SEC) courted controversy by likening London’s junior Alternative Investment Market (AIM) to a casino, Mr Thain appeared to make an implicit criticism of the London Stock Exchange (LSE) for pursuing numerous listings of Russian and former Soviet Union companies.

Speaking in Paris yesterday before the formal launch of the merged NYSE Euronext group today, Mr Thain said: “I am very concerned about the quality of corporate governance, the transparency of company financials and the protection of minority shareholders. A number of Russian companies raise serious questions around these issues.”

Mr Thain declined to comment specifically on the LSE yesterday. However, at the World Economic Forum in Davos this year he criticised AIM for operating low regulatory standards that threatened to harm London’s status as a financial centre.

Twenty-two Russian companies are listed on London’s main market, with a combined value of $437 billion (£220 billion). About half of these have joined since the start of 2006. A further 21 Russian companies are quoted on AIM, with a combined market capitalisation of about $11 billion. Nine of these have joined since the start of 2006.

Last month, Roel Campos, an SEC commissioner, caused controversy by criticising AIM. He said: “I’m concerned that 30 per cent of issuers that list on AIM are gone in a year. That feels like a casino to me. It is a losing proposition to tout lower standards as a way to promote your markets.” Mr Campos also suggested that the LSE would suffer because of AIM’s lax regulation. He said: “There’s also a danger with higher standards; if it’s too affiliated with an exchange that has lower standards, it gets painted with the same brush.”

Critics of Mr Campos pointed out that only about 3 per cent of AIM companies are gone within a year and Mr Campos later said that he had not intended to “smear” London as a financial centre. However, his comments chimed with fears that tough regulations would be forced on the LSE if Nasdaq acquired it.

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