FSG, owners of Liverpool FC, the Boston Red Sox, New England Sports Network (NESN) and 50 percent of NASCAR's Roush Fenway Racing, will partner with James's sports-marketing firm LRMR Branding & Marketing to become the exclusive world-wide representative for the Miami Heat All-Star.
Fenway Sports Management (FSM), the marketing arm of FSG that acquires sponsorships for FSG properties, will team up with LRMR to find global marketing and sponsorship opportunities for James, one of the sporting world's most recognisable people.
As part of the agreement, James will acquire an interest in Liverpool FC, ranked as the sixth most valuable football team in the world by Forbes.
Both parties declined to provide financial details or the size of James stake in the Premier League club.
"We don't see this as a talent representation or an athlete management deal given the structure of this relationship, FSM president Sam Kennedy told Reuters. "We see it more as a business partnership that we formed between our two companies.
"Our role will be business development and selling the LeBron James brand to the corporate market place as we go out to sell the Boston Red Sox, Liverpool, Roush Fenway.
"LeBron adds another blue chip brand to our portfolio."
LRMR chief executive Maverick Carter, a high school friend of the player, said the success of FSM had attracted them to the partnership.
"Everything these guys have gotten involved in has worked and has won," Carter told Reuters.
"The other thing is they are owners and that's what LeBron wants... they are owners and operators and really good at what they do."
FSG chairman Tom Werner said the partnership has targeted emerging international markets such as Asia, which presented opportunities that neither would have been able to realise alone.
"Our goal at Fenway Sports Group is to become the world's most prestigious sports and entertainment company and we took a huge step in that direction when we completed the Liverpool deal," said Kennedy.
"This was a chance to continue down that road to turn Fenway Sports Group into one of the world's most prestigious sports and entertainment companies."
