BENTONVILLE, United States — Wal-Mart Stores Inc is in talks to buy online retailer Jet.com, the Wall Street Journal reported on Wednesday, citing people familiar with the matter.

It was not clear how much Wal-Mart would pay, but Jet.com could be worth as much as $3 billion (£2.25 billion), the WSJ said.

Wal-Mart declined to comment. Jet.com, considered a formidable competitor to Amazon.com Inc, was not available for comment.

Wal-Mart is investing heavily in its online business to take on Amazon, but it has struggled on that front.

The retailer's online business posted its slowest growth in a year in the latest quarter. Wal-Mart's online sales were $13.7 billion in 2015, according to research firm Internet Retailer.

Marc Lore launched Jet.com in July last year, promising big discounts in exchange for members placing large orders and paying an annual fee.

Lore in 2010 sold his diapers-to-soap e-commerce firm Quidsi to Amazon for $540 million.

Wal-Mart shares, which were marginally higher earlier, were off 0.2 percent at $72.96 in late morning trading.

By Sruthi Ramakrishnan; editor: Savio D'Souza.