MEXICO CITY (Reuters) - Mexico’s Supreme Court ruled on Wednesday that Mexican mogul Carlos Slim’s America Movil must allow competitors to use its network and infrastructure, essentially holding up aspects of the 2014 telecoms reform.

Mexican billionaire Carlos Slim holds money as he walks on a street after attending a ceremony to place the first stone of the new U.S. Embassy, in Mexico City, Mexico, February 13, 2018. REUTERS/Edgard Garrido

The court said the obligation imposed by the reform on America Movil, Mexico’s largest telecommunications firm, to lend interconnection services to competitors does not violate its rights.

“Because the constitutional decree itself recognized that there are certain obligations that are imposed on the preponderant economic agent, which will expire once there are conditions of real competition in the market,” it said.

The case was filed by America Movil’s Telmex unit.

A central pillar of President Enrique Pena Nieto’s reform sought to bolster competition by giving other companies free use of Slim’s network, which grew from the former state monopoly he acquired in the 1990s.

The policy was later abandoned by the government after the country’s Supreme Court ruled in August that America Movil’s interconnection rates should be set by the telecommunications regulator, not legislators.

The IFT telecommunications regulator said in November that America Movil would be able to charge rivals 0.028562 peso per minute for calls to its network as of Jan. 1. Competitors can charge 0.112799 peso per minute for mobile calls to their networks, it said.

Rival AT&T Inc calculated that for every peso cent America Movil can charge for interconnection fees, the company’s competitors in Mexico would collectively pay about $20 million per year.

America Movil declined to comment.

Slim holds about two-thirds of mobile phone subscriptions in Mexico.