Terry Smith's interdealer broking firm Tullett Prebon was today forced to admit it has received a takeover approach after its shares shot up in value.

The share price jumped 17%, or 52¼p, to 362½p valuing the group at £780 million.

Speculation immediately centred on Australian financial services giant Macquarie, which was reported to be looking at taking over the world's second-largest interdealer brokership in February.

But Bank of China was also put in the frame by some dealers as it seeks to extend its international operations.

Speculation also centred on GFI, the New York-based brokership founded by Essex-born Mickey Gooch, which held merger talks with Tullett almost two years ago.

But then Smith was the driving force behind the £1.6 billion merger deal, looking to buy out Gooch's 43% stake in the fourth-biggest IDB in the world.

Analysts said it was unlikely that GFI could be the aggressor this time around.

Tullett issued a statement to the Stock Exchange on the orders of the Takeover Panel.

It said: “Tullett confirms that it is in preliminary discussions with a third party which may or may not lead to an offer being made for the entire issued share capital of the company.”