Sept 13 (Reuters) - The world's largest online betting

company Flutter said on Friday it will buy a 56% stake

in NSX Group, the operator of Brazilian gaming group

Betnacional, for about $350 million as it seeks to expand in the

soon-to-be regulated market.

Flutter, owner of FanDuel and Paddy Power, said it would

merge Betnacional with its existing Betfair Brazil brand and

invest heavily to drive market share growth, similar to its

strategy in the U.S. where it is now the No. 1 operator.

Sports bets were legalized in soccer-mad Brazil in 2018

but will only be full regulated in early 2025. Dozens of betting

brands, including Betfair, bet365 and Betano, have been

aggressively expanding in the country in recent years.

NSX is the No. 4 player, with a 12% share of the sports

betting market. It is expected to generate revenue of around

$256 million in 2024 - more than three times that of Betfair

Brazil - and a core profit of around $34 million in 2024,

Flutter said.

Flutter, which will be able to increase its shareholding

after five and 10 years of completing the deal, said it expected

the new Flutter Brazil unit to make a loss of around $90

million-$100 million in 2025 due to its investment drive.

The Irish betting group said last month that it also in

talks to buy UK gambling technology firm Playtech's ( PYTCF )

Italian unit Snaitech.