Global Payments is buying Total System Services in an all-stock deal valued at $21.5 billion, the third major acquisition in the payment processing sector this year.

TSYS shareholders will receive 0.8101 Global Payments shares for each share of TSYS common stock, about a 20% premium to TSYS's common share price at the close of business on May 23, 2019.

Upon expected closing in the final quarter of 2019, Global Payments shareholders will own 52% of the combined company, and TSYS shareholders will own 48%.

The combined companies will provide payment and software technology to about 3.5 million small-to-mid-sized business and more than 1,300 financial institutions.

In March, Fidelity National Information Services announced it was acquiring Worldpay and Fiserv bought First Data in January.