Marc Lore, the CEO and founder of Jet.com. Jet Walmart is buying Jet.com in the largest e-commerce acquisition in history.

Walmart will pay about $3 billion in cash plus about $300 million of Walmart shares for the two-year-old e-commerce site.

"We're looking for ways to lower prices, broaden our assortment, and offer the simplest, easiest shopping experience because that's what our customers want," Walmart CEO Doug McMillon said in a statement.

Jet.com CEO and cofounder Marc Lore will continue to play a key role at the company, according to CNBC. He owns about a quarter of Jet.com and could make as much as $750 million from the deal, according to Recode.

"The combination of Walmart's retail expertise, purchasing scale, sourcing capabilities, distribution footprint, and digital assets — together with the team, technology, and business we have built here at Jet — will allow us to deliver more value to customers," Lore said in the statement.

He previously cofounded Quidsi, which runs the e-commerce sites Diapers.com, Soap.com, and Wag.com.

As Business Insider's Eugene Kim previously reported, the deal should help boost Walmart's online business, which has struggled to gain much traction against Amazon, the market leader. Walmart has generated about $14 billion in annual e-commerce sales, compared with Amazon's $99 billion in annual revenue.

T-shirts made in the USA are on sale for $4.88 at the Walmart Supercenter in Bentonville, Arkansas June 5, 2014. Reuters/Rick Wilking , which has raised more than $500 million, has tried to position itself as an Amazon competitor, reportedly having set a goal to become a $40 billion company within five years. It was most recently valued at about $1 billion.

Jet.com's products are typically priced 10% to 15% lower than those of its competitors, though that costs tens of millions of dollars a month in marketing. The company recently pivoted away from a $50-a-year subscription model in hopes of reaching more customers, which put even more pressure on its cost structure.

Walmart and Jet.com will maintain distinct brands, according to Monday's statement, with Walmart.com focusing on its everyday-low-price strategy and Jet providing a "unique and differentiated customer experience with curated assortment."

Allen & Co. and JPMorgan advised Walmart on the deal, which is expected to close sometime this year, pending regulatory approval.

Walmart will release second-quarter earnings on August 18.