Cox has increased its stake in Insurancewide.com which provides a range of insurance products including motor, home and travel insurance on the Freeserve site.
Cox now owns 40% of the company, with Global Net Financial.com holding 30%, Freeserve, 19.9% and Harrison Son Hill
& Co 10.1%.
Neil Uttley, chief executive of Cox's retail division, would not say how many policies the site was generating or whether the company would expand its share.
Cox also owns the personal lines site insure.co.uk which generates sales of £500,000 a week and is set to launch brokersure.co.uk to intermediaries.