The purchase marks the latest example of Accor's recent acquisition spree, with the French group agreeing to buy Chile's Atton Hoteles last month and also looking at taking a minority stake in Air France KLM.
AccorHotels said the SBE stake would raise its profile in cities such as Los Angeles, Miami, Las Vegas and New York, and give it access to SBE's fashionable millennial clientele.
Nazarian, who grew a collection of Los Angeles nightclubs in the early 2000s into an international hospitality empire, has secured a reputation for being in vogue via his partnerships with trendy designers such as France's Philippe Starck.
He will continue to run SBE and own the remaining 50 percent of the group.
SBE's brands include well-known brands such as the Delano, Mondrian and the Hyde Bellagio in Las Vegas.
AccorHotels will buy 50 percent of SBE's common equity held by Cain International for $125 million and also invest $194 million in a new debt instrument, making a total investment of $319 million.
Accor shares advanced 0.6 percent by mid-session trading.
"The portfolio is a good foil for Fairmont (Accor's existing luxury brand in the U.S), with the SBE brands being more millennial and leisure/resort focused," wrote analysts at brokerage Bernstein in a research note.
This expansion, however, came at a price, they cautioned.
"Accor is using the cash from its asset sale to buy more hotel assets (against its plan to be more asset light)," said Bernstein.
Meriem Mokdad, fund manager at Roche Brune Asset Management, which recently sold its Accor shares, also expressed concerns at the fact that Accor did not give any details of how the SBE stake might lift its earnings.
In February, AccorHotels agreed to sell 55 percent of its AccorInvest property business to sovereign and institutional investors for 4.4 billion euros, saying it would use part of the cash to fund acquisitions.
Previous acquisitions under AccorHotels' chief executive Bazin, who took over in 2013, include London's Savoy Hotel, The Plaza in New York, the Raffles Hotel in Singapore and Australian hotel group Mantra.
(Reporting by Sudip Kar-Gupta; Editing by Sunil Nair, Michel Rose and Jan Harvey)
By Sudip Kar-Gupta and Dominique Vidalon