(Adds details from statement, shares and market value)

MEXICO CITY, July 26 (Reuters) - Mexico's Grupo Carso, controlled by the family of billionaire Carlos Slim, will begin the process of buying the shares of retail department store unit Sanborns it does not already own, the company said in a statement on Tuesday.

The purchase of the shares will allow the retail subsidiary to delist from Mexico's stock exchange, in line with the company's interests, a spokesperson told Reuters.

Carso said available stock in Grupo Sanborns will be purchased for 26 pesos ($1.27) per share, a plan Carso's shareholders approved on Monday, according to the statement.

Shares in Sanborns closed Tuesday at 22 pesos on the Mexican stock exchange.

The Slim family already owns 87% of Grupo Sanborns, which also operates Sears department stores in Mexico and El Salvador, while Slim's Inbursa bank owns another 6.7%, according to data from Refinitiv Eikon.

Grupo Sanborns' market capitalization stands at about 50 billion pesos ($2.44 billion).

In Mexico, both the Sanborns chain and Sears stores are upscale retailers.

($1 = 20.4539 Mexican pesos) (Reporting by Carolina Pulice and Kylie Madry; Editing by David Alire Garcia and Leslie Adler)