Carlos Slim holds a majority interest in America Movil.

America Movil SAB de CV (AMX - Get Report) shares are up 0.73% to $18.04 in afternoon trading on Friday after a Mexican Supreme Court justice suggested that the court may restore interconnection fees that the country's Congress eliminated.

The proposal by Justice Javier Laynez argues that any rule change should not be retroactive, which would result in Movil forfeiting an estimated $800 million in lost revenue from the fees, according to Bloomberg estimates.  

Carlos Slim, one of the world's richest people and one of the New York Time's (NYT - Get Report) largest stakeholders, controls America Movil. 

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