Speculation mounted this week that JLT is set to buy rival Heath Lambert. Sources said JLT was in the early stages of discussions with the company. A spokesman for Heath Lambert denied the suggestions as "rumour".

Analysts, however, said the move would be a good one for JLT, as it could generate cost savings and help it to head off any acquisition bids against it.

New chief executive Dominic Burke has said that acquisitions could form part of its business strategy.

JLT has a market captialisation of £780m, while it is believed Heath Lambert is valued at around £130m. JLT has already acquired most of Heath Lambert's Latin American and aviation operations.

The broker has been linked to Alexander Forbes. Sources said the UK arm of the Alexander Forbes was up for sale, with the deal being handled by bank JP Morgan.

One source said: "We understand Jardine Lloyd Thompson and Willis are in the frame. There are a number of rumours flying around right now, but this one seems most likely."

A spokesman for Alexander Forbes denied the rumour as "pure speculation".

JP Morgan refused to confirm if it was involved in the alleged deal.

Commenting on the Forbes speculation, analyst Roman Cizdyn at Oriel Securities said: "I'm a bit surprised to hear this.

"A number of South African companies have been building up their operations overseas. South Africa is a relatively small market and it would appear to make sense to be in London."