NEW YORK (AFP) - Joseph Tsai, one of the founders of Chinese e-commerce giant Alibaba, is set to buy 49 per cent of the National Basketball Association's Brooklyn Nets, US media reported Friday.

ESPN and Newsday both reported that Russian billionaire Mikhail Prokhorov, who purchased controlling interest in the cub in 2009, has agreed to the sale.

Although the Nets had the worst record in the NBA last season, a source told Newsday that the deal values the franchise at US$2.3 billion (S$3.14 billion).

That tops the US$2.2 billion sale of the Houston Rockets earlier this year in a deal that included their Toyota Centre arena.

Under terms of the Nets sale first reported by ESPN, Tsai can choose to purchase a controlling interest in the Nets after four years, but not necessarily 100 per cent ownership.

Prokhorov, who retains full ownership of the Barclays Centre arena, could retain a minority stake in the team in the future and remain in control of team operations and the management team he installed more than a year ago headed by general manager Sean Marks and head coach Kenny Atkinson.

ESPN reported that it obtained NBA financial documents that show the Nets lost US$144 million on basketball-related activities in the 2013-14 season, a figure more than US$100 million higher than any other franchise. The Nets' operating loss of US$23.5 million last season was higher than any other team except the Detroit Pistons.

This season, the outlook is brighter for the team thanks to an increase in television revenues of nearly US$50 million, in part the result of increases in the NBA's national television contract.