American regulatory filings show that 35 foreign companies have delisted from American stock exchanges since April.

Rising costs, over-regulation and a culture of litigation have been cited as reasons for the exodus. In addition, US investors are preferring to buy stocks directly in overseas markets rather than from secondary listers in America.

British Airways, Danone and ICI have all described multiple accounting standards, lower trading volumes and near-draconian compliance under Sarbanes-Oxley law as reasons for turning away from secondary listings.

London is seen as the main beneficiary of this trend.

The London Stock Exchange retained its number one spot as the world’s most successful borse in the first half of the year.

A report from Dealogic gives the LSE initial public offerings worth £16.8bn ($34bn), compared with New York’s £15.1bn ($31bn). Hong Kong trailed in third place with just £7.4bn despite its proximity to the burgeoning Chinese growth engine.

With reports that this bonanza may have peaked, especially from Russia, Michael Long, an analyst with Keefe, Bruyette and Woods, said : “There is a concern that a lot of the Russian listing is a bit bubbly.”

However, he didn’t see much sign of New York improving its relative market share on IPOs. “It’s cheaper to do them here, regulations are less complicated and strenuous, and they argue there’s a bigger international investor base here than in the U.S.”

The good times continue.

IdaTech, an Oregon fuel-cell company will bypass the New York stock markets, Nasdaq and the NYSE, and list on the London Stock Exchange. The flotation is valued at £100m ($195m).

Observers believe this is another sign that America’s draconian Sarbanes-Oxley legislation is proving a turn-off for U.S. firms.

IdaTech manufactures environmentally friendly generators for industry and for recreational use. Owner Investec, with 96 percent of the stock, is selling between 50 and 60 percent of its holdings.

Following Nasdaq’s £1.9 billion ($3.7bn) deal to buy Swedish exchange OMX, which operates in Iceland, the Baltic states and Scandinavia, Dubai has muscled in on the act.

The Dubai International Financial Centre is said to be “the world’s newest international financial centre”. It has appointed HSBC to advise it on a possible challenge for OMX.

On Friday, OMX agreed to be taken over by Nasdaq, the New York exchange, which last year made two failed attempts to buy the London Stock Exchange.

The Nasdaq cash and share deal for OMX would have created a £3.8 billion ($7.5bn) company with operations in eight countries. It would be the third transatlantic merger between exchanges in the past 12 months.

The Times (London) reports, “The DIFC’s decision to consider a counterbid further underlines the international ambitions of the tiny Gulf state. Last year, Dubai Ports World, another arm of the Dubai government, seized control of some of the world’s most important ports when it acquired P&O. The planned bid for OMX signals DIFC’s ambitions to raise Dubai’s profile in international financial markets.”

The Dubai International Financial Exchange, which opened for business in 2005 was intended to “create an environment for progress and economic development in the UAE and the wider region”.

So, the consolidation of the world’s stock markets proceeds apace. In March the New York Stock Exchange completed its acquisition of Euronext, the pan-European borse. Nasdaq claims still to have ambitions to bid for the LSE, but is prevented by City regulations from bidding again until next February.

A combination of OMX, which is being advised by Credit Suisse and Morgan Stanley, and the slightly larger Nasdaq, being advised by JP Morgan, would create a company worth 30% more than the LSE, which has a market value of £2.7 billion. OMX has a derivatives business that ranks behind NYSE Euronext’s Liffe, and Eurex, controlled by Deutsche Börse. It is considered particularly attractive by other exchanges because of its innovative financial-trading technology.

Nasdaq is planning to use new generation OMX technology as a base for the group, which would, it claims, deliver two-thirds of the £76m ($150m) that may be gained from the merger.

Dubai, however, might just have the last word.