Today the handcuffs come off in Nasdaq’s bid to take the London Stock Exchange. With 25.3pc of LSE shares, the American exchange can bid for the rest at £12.43 per share.

However, sources close to Nasdaq say it can’t afford to buy at that price, so is likely to sit out the next six months. The New York-based company is already heavily in debt and may refuse to gamble, especially as it is now known the British Government intends to legislate to protect London from the onerous American Sarbane-Oxley rules and may pack off any bid to the Competition Commission.

The Times (London) reports : “… there were signs at the weekend that some investors were taking the view that, in the short term at least, the LSE share price could fall in the absence of a bid or an agreed deal. About 12 per cent of the shares are the subject of stock borrowing, a technique that is often used to go short in a share in the expectation of a fall.”

Speculation grew that Clara Furse may seek a deal with a Far East exchange.

A tie-up between the London Stock Exchange and Icap, the world’s largest inter-dealer broker, has been discussed during the summer, it has emerged.

Icap is expected to confirm today that talks have taken place. The main sticking point seems to be the current share price of the LSE, which, at more than £12 ($22.56), has all but doubled this year.

A merger would create a formidable all-British heavyweight valued at £6 billion ($11.28bn), with a strong derivatives base. It would, at a stroke, make up for the strategic defeat of losing Liffe to Euronext.

However, the complementary nature of the parties means that cost savings would be hard to find. Whereas Nasdaq might justify the high price of a bid (£12.43 is the floor price it must pay in the near term) by savings derived from rationalization, Icap would see a dilution in value after any deal.

Clara Furse, the LSE chief executive, has a lot of balls in the air as the autumn season gets underway. Buying the Scandinavian exchange OMX, is one option; various possibilities involving private-equity outfits also beckon, plus the tempting prize of Icap.

Over-arching all, however, is the American Nasdaq, which, with 25.3pc stake and a clear field of play from next Monday, remains the one to be beaten.

The total value of all shares quoted on the London Stock Exchange shrank by £47 billion in the first half of the year.

Citigroup analysts calculated that £64 billion of equity was lost to the market through a barrage of takeovers, buybacks and special dividends. That number dwarfed the £18 billion gained through share sales.

John Thain, CEO of the New York Stock Exchange, has said he will not improve terms of its £10.7 billion merger with Euronext, despite noises from rival Deutsche Borse that its proposal was worth more.

The Times (London) reports: “Speaking to journalists in New York last night, and reported by AFP, Mr Thain said he noted continued moves by Deutsche Borse to lure Euronext away from the agreed merger but said he would not increase his offer price, whatever plan the German exchange came up with.”

Euronext said: “This first half of the year has been the best one ever for cash and derivatives markets and has created the conditions for all business lines to register an increase in their revenues. This strong performance has been achieved in spite of the impact of changes in the scope of consolidation.”

Euronext’s Chief Executive, Jean-Francois Theodore, and John Thain have said they are on course to complete their landmark merger during the first quarter of next year.