Fidelity National Information Services has agreed to buy Worldpay for about $35 billion, with the US financial services provider striking the biggest deal to date in the fast-growing electronic payments industry. 

The financial technology sector is consolidating fast.

Global payments are set to reach $3 trillion a year in revenue by 2023 as more people switch from cash to digital payments for online and high street sales. 

"Scale matters in our rapidly changing industry," said FIS chief executive Gary Norcross, who will lead the combined powerhouse in banking and payments infrastructure. 

Growth in payment systems has kept deals rolling even as merger moves in other sectors have stalled on concerns about trade tensions and a global economic slowdown. 

The FIS deal, valuing Worldpay at about $43 billion including debt, comes a little more than a year after US firm Vantiv paid $10.63 billion for the payments firm.

Worldpay had been set up in Britain and spun off from Royal Bank of Scotland in 2010. 

And in January, US-based Fiserv Inc bought payment processor First Data Corp for $22 billion, while Italy's Nexi plans to list in what could be one of Europe's biggest initial public offerings (IPOs) this year. 

FIS and Worldpay combined will have annual revenue of about $12 billion and adjusted core earnings of about $5 billion. 

"Vantiv had yet to realise all the synergies from the Worldpay merger but FIS's offer was too good to be refused," a source close to the deal said. 

Worldpay is a major player in card payments, particularly in Britain, while FIS, produces software for banks and asset managers as well as its financial services outsourcing business. 

Worldpay shareholders will receive 0.9287 FIS shares and $11 in cash for each share held, valuing the company at $112.12 per share, a premium of about 14% on its Friday close. 

FIS shareholders will own about 53% in the combined firm and Worldpay's about 47%, with Worldpay Chief Executive Charles Drucker becoming executive vice-chairman.