RedBird Capital Partners, the private investment firm part-owned by the NBA star LeBron James, has bought a stake in Fenway Sports Group for about $735m (£533m), Liverpool’s owners have confirmed.

FSG has been in negotiations with RedBird for several months as it sought investment to cushion the financial impact of the pandemic, which is understood to have cost Liverpool £120m in lost revenue over the past year. That figure is set to increase and the deal with RedBird, which will become the third-biggest partner in FSG, will enable Liverpool to continue with plans to redevelop the Anfield Road stand and invest in player recruitment at pre-pandemic levels.

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RedBird’s investment is based on a valuation for FSG of $7.35bn (£5.33bn). Liverpool’s owners believe the deal will provide continuity and stability for the organisation, rather than simply a windfall for the football club or the Boston Red Sox baseball team they own, with several shareholders diluting their stake to allow James, Maverick Carter and their longtime business partner Paul Wachter to become part of the FSG ownership group.

The Red Sox president and chief executive officer, Sam Kennedy, will also become a partner in FSG. RedBird, founded by the former Goldman Sachs partner Gerry Cardinale, has purchased about 10% of FSG. A portion of the investment will be new capital that will allow FSG to reduce the debts incurred over the past 12 months. That in turn will safeguard Liverpool against any risk to the proposed £60m redevelopment of the Anfield Road stand as a consequence of the global financial crisis.

A statement from FSG’s leadership – comprising the principal owner, John W Henry, the chairman, Tom Werner, and the president, Mike Gordon – read: “Our strategic partnership with Gerry and the entire team at RedBird will enhance our ability to pursue future growth opportunities in a more accelerated way but with the same selectiveness that has served us so well.

“We are also pleased to welcome to our ownership group LeBron, Maverick and Paul, with whom we have enjoyed a successful collaboration for well over a decade. Their addition is an important milestone for FSG and expands and deepens a longtime friendship and relationship that began in 2010.

“To our fans and supporters: winning continues to be the driving force for all of us. The growth of FSG as an organisation allows us to further strengthen our resources and commitment to the communities we serve, and we look forward to having these talented new partners join us in the next chapter of FSG’s evolution.”