The undisclosed takeover of the business enables Citation, the health and safety, employment law and HR service provider backed by ECI Partners, to enhance its range of services by adding accredited ISO certification to its offering.

It also increases its client base by two thirds to more than 15,000.

This is Citation's second acquisition, following the takeover of Bibby Consulting & Support in 2013.

The QMS brand will be retained and the company's 60 employees will remain at the head office in Norwich.

Citation chief executive Chris Morris said: "QMS International has an excellent reputation as an accredited ISO organisation. The company is established and well-known nationally, making it a good fit with Citation.

"As a business we are always looking to acquire successful companies that complement the services offered by Citation. We actively seek out solid investments and welcome the opportunity to diversify into new sectors, as this enables us to expand our product offering adding real value to our clients. This acquisition is a primary example of a great partnership between two like-minded, ambitious businesses and I am confident it will bring future growth to both companies."

Richard Chapman, head of business services at ECI and board director at Citation, added: "We are delighted to be backing the team at Citation to make another acquisition.

"This highlights our commitment to supporting the teams we back to make strategic investments which has been continuously demonstrated over the last few years during which our portfolio companies have made fourteen acquisitions."