A leading digital company has bolstered its business in a reported £10 million deal.

Social media monitoring company Brandwatch, based in Church Street, Brighton, has acquired PeerIndex, a London-based analytics company previously valued at £5 million.

The deal is unusual because it is typically Brighton digital companies that are acquired by bigger London or US businesses once they reach a certain size.

It takes the headcount at Brandwatch to more than 300 employees, most of which are based in Brighton, but also in offices in New York and Berlin.

The combination of two UK companies is rare for the tech sector outside Silicon Valley.

The city's digital sector is thought to be growing at ten times the rate of the UK economy.

All PeerIndex employees will become Brandwatch ones, which will give the Brighton company a London presence.

The news follows an announcement earlier this year of a £13 million finance injection at Brandwatch.

The company also moved to bigger offices in Sovereign House and revealed plans to recruit an extra 100 people in the city.

The global headcount of the combined company is now 300.

Customers of Brandwatch, one of the world's leading social intelligence companies, include British Airways and Pepsico.

Its technology enables marketers to understand more about the people behind the conversations happening online PeerIndex was chosen as its first acquisition for its complementary technology and talent.

Peerindex has the world's largest independent Twitter author database and its technologies and specialist engineering team will be absorbed into Brandwatch.

Giles Palmer, Brandwatch chief executive, said: "For over half a decade we've been building some of the most advanced and acclaimed technology on the market, right here in Brighton.

“There are over a thousand companies across the globe now using the products we've made, and I'm proud to be welcoming another UK tech success story into our family.

“PeerIndex are exactly the kind of company we want to be partnering with, and in them we've found a group of people that match our ambition."

Phil Jones, managing director of Wired Sussex, said: “We have seen examples of Brighton companies being snapped up by London companies with Origami Blue being bought by Mindy Candy a recent example, but this role reversal is further proof of the digital powerhouse that Brighton is rapidly becoming.

“Brandwatch is a great ambassador for the Brighton cluster.”