SoftBank Group Corp. said it has agreed to take a majority stake in Line Corp.'s mobile unit for an undisclosed sum.

The deal, to be finalized around March, will give SoftBank Corp. — the Tokyo-headquartered telecom and technology conglomerate's mobile phone subsidiary — 51 percent ownership of low-cost carrier Line Mobile Corp. through an issuance of new shares. Line, which operates the messaging application of the same name, will hold the remaining 49 percent.

Competition in the domestic telecoms market has ramped up in recent years with the emergence of virtual network operators which buy capacity from the three major carriers — NTT Docomo Inc., KDDI Corp. and SoftBank — at wholesale prices and sell to users.

The tie-up between SoftBank and Line is part of an industry-wide reshuffle, with e-commerce giant Rakuten Inc. acquiring low-cost carrier brand Freetel Co. and announcing in December it intends to become the country's fourth major carrier.

Line separately said Wednesday it had established a new financial unit that will make loans and sell insurance, with plans to set up a cryptocurrency exchange.

The announcement comes in the wake of the theft last week of roughly ¥58 billion in virtual currency from a Tokyo-based exchange.