LONDON, Dec 5 (Reuters) - Britain on Thursday approved

the $19 billion merger between Vodafone UK and

Hutchison's Three UK to create the country's biggest

mobile operator and reduce the number of networks to three from

four.

The Competition and Markets Authority had previously said

the deal could push up customer prices, but it later accepted

that a pledge by the two companies to invest in 5G networks and

offer protections for retail and wholesale customers were enough

to ease its concerns.

"We believe the merger is likely to boost competition in

the UK mobile sector and should be allowed to proceed - but only

if Vodafone ( VOD ) and Three agree to implement our proposed measures,"

it said.

The approval follows a demand by Prime Minister Keir

Starmer that regulators put the need for investment and economic

growth at the forefront of their thinking.

Vodafone ( VOD ) and Three have committed to spend 11 billion

pounds ($14 billion) to build a better 5G network that will

serve 50 million customers, including the subscribers of

Vodafone's ( VOD ) network sharing partner Virgin Media O2.

The CMA said the investment would boost competition

between the three remaining networks, which includes current

market leader BT, and deliver a better service for

customers.

Vodafone's ( VOD ) Chief Executive Margherita Della Valle said

the green light would unlock the investment needed to build the

network infrastructure Britain deserved.

"Today's approval releases the handbrake on the UK's

telecoms industry, and the increased investment will power the

UK to the forefront of European telecommunications," she said.

Vodafone ( VOD ) will own 51% of the combined company and will

have an option to buy the remainder after three years following

completion and subject to certain conditions.

($1 = 0.7859 pounds)