Worldpay's £4.8bn float is top City deal of the year
Payments processor Worldpay became the biggest flotation in the City this year when it listed on the London Stock Exchange at a value of £4.8bn.
Stock in the firm was initially offered at 240p a share, after its private equity owners Advent International and Bain Capital sold about a 51% stake in the business.
The share sale will raise up to £2.5bn, of which £948m will go to the company.
It said it intends to use the cash to expand into new markets and develop its payments systems.
Worldpay processes around 31 million mobile, online and in-store transactions every day. It employs about 4,500 staff, mostly in Britain and the US, which are its two biggest markets.
Advent International and Bain Capital were reported to have rejected an offer of up to £6.6bn, including debt, earlier this year from French rival Ingenico Group.
Worldpay chief executive Philip Jansen called the flotation a "significant milestone" for the business. Mr Jansen added: "We are proud to be a leader in global payments with a clear strategy for continued growth as a listed company.
"We have already invested over £1bn in our technology, people and capabilities, helping us to become an advanced and sophisticated technology-led organisation with great potential."
Prime Minister David Cameron added: "It's fantastic news that Worldpay has listed on the London Stock Exchange - the largest ever UK FinTech initial public offering. This shows real confidence in our long term economic plan and helps cement London as the world's leading location for this sector."
Advent International and Bain bought Worldpay from Royal Bank of Scotland in 2010 for about £2bn.