The U.K.'s Competition and Markets Authority said Tuesday that Vodafone and Three's £15 billion ($19.5 billion) merger will likely be approved if the two firms proceed with billions of pounds of infrastructure investment and add customer protections.

Vodafone Group’sVOD-0.22%decrease; red down pointing triangle deal to merge its U.K. business with rival operator Three can move forward if competition concerns are addressed through network investment and customer protections, the U.K.’s antitrust ...

The $19 billion merger between Vodafone and Hutchison's Three UK is likely to be given the regulatory green light as Britain's need for investment outweighs short-term competition concerns.Britain's anti-trust regulator said on Tuesday it believed the combination of the country's third and fourth biggest mobile operators could be "pro-competitive" if certain measures and remedies are implemented.