Alan Hughes, MD of Axzona , said: it was " great news for customers of both companies. Site Confidence is the market leader in the UK, serving a broad customer base. It has a wide variety of excellent website performance services, which we look forward to introducing our customers to in coming months.

Bob Dowson, operational director Site Confidence , said: "We are very pleased that Axzona has chosen to join the Group. Together, our broad and complementary services will help customers across a wider range of website performance optimisation needs."

Last month NCC Group, the escrow and assurance services business, provided preliminary results for the year to 31 May 2011 in which group revenue  rose  49% to £71m and adjusted profits  up 21% to £17.3m.

Assurance testing presents a number of opportunities for the business to grow, given the rise of malicious and illegal activities across the internet, and the development of its website performance adds to the company's repertoire.