MEXICO CITY, June 28 (Reuters) - Brazilian retailer GPA said on Wednesday it had received an unsolicited offer from Colombian business magnate Jaime Gilinski to take over its subsidiary, Almacenes Exito, in a deal worth $836 million.

GPA said in a securities filing its board of directors would study the binding cash offer for its 96.52% holding in Exito, which expires on July 7.

Exito, which operates South American supermarkets and shopping malls, has a market value of some $1.3 billion, according to Refinitiv data.

GPA had announced preliminary steps to divest the company late last year. The steps to divest came as GPA's French parent company, Casino planned to simplify its Latin American operations in order to cut its debt.

Last year, Casino's Latin American business brought in just over half its $36.6 billion revenue. The company employs three-quarters of its workforce and has more than 3,000 stores across the region.

Earlier on Wednesday, Casino set a July 3 deadline for offers to boost its equity.

One is from main shareholder Jean-Charles Naouri who has teamed up with French billionaire Xavier Niel and another is from billionaires Daniel Kretinsky and Marc Ladreit de Lacharriere. ($1 = 0.9173 euros) (Reporting by Carolina Pulice and Sarah Morland; editing by Robert Birsel)