The Competition Markets Authority (CMA) said today that it has until 16 August to decide if the proposed sale will be enough to address its antitrust concerns, or refer the merger for further investigation.
Icap will no longer retain a 19.9 per cent interest in the combined group, with shares instead being issued directly to Icap investors.
This means Icap shareholders will now hold about 56 per cent of what will be called Nex Group if the deal completes, according to a statement from the firms.
The CMA said earlier this month that the proposed deal would be referred for an in-depth investigation if the two firms didn't address the watchdog's competition concerns relating to the overlap in voice/hybrid broking oil products.
It came after Icap and Tullett announced the £1.1bn deal last year to better compete in a sector where trading volumes have been shrinking.