Rakuten Inc. got the green light Friday from a government panel to become the nation’s fourth major wireless carrier, granting the e-commerce giant access to a fierce competition for subscribers alongside industry heavyweights who have long dominated the cellular market.

An Internal Affairs and Communications Ministry advisory board approved Rakuten’s application for a 4G mobile license, which the company had submitted in February. The decision is expected to be formally endorsed by the ministry at a later date, marking the first time a new entrant has been approved since eAccess — now a part of SoftBank Group Corp. — was granted bandwidth 13 years ago.

The move threatens to disrupt Japan’s mobile phone market oligopoly of NTT Docomo Inc., KDDI Corp. and SoftBank Corp., the last of the three being the domestic arm of tech mogul Masayoshi Son’s global telecommunications and internet empire.

Rakuten aims to start offering mobile services in 2019, and plans to secure up to ¥600 billion to invest in base stations. It hopes to acquire at least 15 million customers in 10 years and differentiate itself from rivals through affordable pricing and its point-based loyalty program, which spans the firm’s myriad services ranging from e-commerce to financial technology.

But while the company hopes its mobile business will become a new growth engine, experts said it will likely face an uphill battle in a saturated market.

“In the first place, Rakuten’s entry is a defensive strategy,” said Mitsunobu Tsuruo, an analyst at Citigroup in Tokyo. He said the company is compelled to diversify its services to fend off increased competition from rivals Amazon Japan and Yahoo Japan Corp. — the latter being part of the SoftBank group — that has been eroding Rakuten’s market share in online shopping.

Rakuten aims to maintain its edge by acquiring a new customer base through its mobile business, Tsuruo said.

“For that, it needs to grow relatively quickly since the mobile business is all about scalability. If Rakuten can’t beat the other three in network quality, it will need to fight with aggressive pricing,” he said.

With the population graying and shrinking, Rakuten will likely have to pry subscribers from existing players to reach its target of 15 million. Plans offered by the three companies have also become identical over the years, meaning Rakuten’s entry could ignite a new price war — a welcome development for a government worried about mobile phone fees weighing on households.

The cybermall operator, headed by billionaire entrepreneur Hiroshi Mikitani, already has a mobile virtual network service that rents space from companies with licenses to offer discount rates. But its customer base — 1.4 million — is a far cry from the subscriber numbers boasted by any of the big three carriers.

According to the Telecommunications Carriers Association, NTT Docomo had 75.68 million subscribers as of December, followed by KDDI with 50.64 million and SoftBank at 39.5 million.

But Rakuten’s advantage may be its wide range of businesses and large online user base that could sign up for its mobile service in return for other perks, said Hitoshi Sato, senior analyst at InfoCom Research.

“The benefits of running a telecoms business is the steady revenue, but it requires balance since excessive discounts could make it difficult to recoup capital investment,” he said.

Rakuten plans to build communications infrastructure in stages, beginning with investments in stations in urban areas with large populations.

Over the past weeks, the online retailer has also announced a string of tie-ups, to cut costs, with power companies including Tokyo Electric Power Company Holdings Inc., which will allow Rakuten to use the energy firm’s facilities as transmission towers, utility poles and telecommunications towers.

Rakuten has entered similar agreements with Chubu Electric Power Co. Inc. and Kansai Electric Power Co. Inc. to establish a network of base stations.

Rakuten, founded by Mikitani in 1997, has been expanding its global business through acquisitions of e-commerce sites like Ebates Inc. and messaging app Viber, and by investing in ride-hailing service Lyft.

In Japan, it bought Asahi Fire & Marine Insurance Co. this year to boost its portfolio of financial services and struck a partnership with Wal-Mart Stores Inc. to launch an online grocery delivery service.