The UK's competition regulator has called in Paypal's $2.2bn (£1.7bn) acquisition of Swedish payments firm iZettle on the day it completes.
The Competition and Markets Authority (CMA) will investigate whether the merger would lessen competition between payment platforms in the UK, with the firms remaining separate until the CMA concludes its probe.
Nevertheless, Paypal said the acquisition would help it expand its business services to include smaller firms.
Bill Ready, chief operating officer, said: "We're thrilled to welcome the iZettle team to the PayPal family and are excited to expand the ways we serve our small business customers.
"iZettle brings a suite of products and services that allows merchants to meet their customers where they are – online, in store or via mobile. This is another step in our journey toward democratising commerce tools to help businesses of all sizes thrive."
The firm, which allows small businesses to take card payments, had planned to IPO in Sweden to raise £168m, but three weeks after its May announcement Paypal pounced.
Co-founder Jacob de Geer will continue to lead iZettle at the online payments giant, reporting into Ready.
However, that won’t happen until the CMA completes its investigation and finds nothing wrong with the merger – it stipulates that “no changes are made to key staff” until the probe is over, while the firms must remain separate entities.
"Today is a very big day – for me and for everyone at iZettle," de Geer said. "We share PayPal's strong belief in the power of small businesses. Together, we will be stronger and move even faster to help small businesses succeed in a world of giants."