Britain's ICAP, the World's biggest interdealer broker, augured its full-year earnings below expectations on Friday; revealing new businesses were consuming longer than anticipated to become profitable.

It shares plunged by 16.2 percent at 829 GMT after broker said underlying full-year profit would be between 295 million and 315 million pounds.

However, the Financial Services Authority has preferred to remain silent on its plans to investigate Mr. Spencer's share sale.

Nitin Arora, an analyst at Noble Group cited, "It's difficult to spot any positive news. It's negative on all fronts", he said, adding the data suggested e-broking volumes were not picking up as expected.

ICAP reports group revenue as marginally ahead for the third quarter to end-December from a year ago, citing a new business segments to be unveiled, which offset a decline in core voice revenues.

ICAP said it would also pay about 12 million Euros toward working capital as well as two possible payments based on revenue and profit targets for the period to end-December 2012.

ICAP also unveiled its latest acquisition to buy the remaining share capital of TriOptima with a view to boost its business of providing post-trade processing services for the derivatives markets.

Stockholm-based TriOptima AB acts as the repository for the interest rate swaps market and is a leader in compression, a process that helps banks reduce the number of outstanding credit default swaps contracts to reflect underlying net risk exposures, among other businesses.