The use of commercial fracking in Colombia could boost oil and gas reserves by between 12 and 15 years, majority state-owned oil producer Ecopetrol said on May 5, adding it expects a ruling on the suspended environmental license for a fracking pilot project to come in June.

Supporters of hydraulic fracturing - also known as fracking - say its output is key to shoring up Colombia's energy self-sufficiency, which counts on less than seven years of reserves, while opponents warn of pollution and decry threats against environmentalists.

The country's top administrative court has permitted investigative pilot projects by Ecopetrol and partner Exxon Mobil Corp. to go ahead while it weighs whether to allow commercial development.

The national environmental regulator issued a license for the Kale pilot project in March but a judge later ordered it suspended on grounds that local communities were not properly consulted.

The ruling, which was appealed by Ecopetrol, also ordered that a local Afro-Colombian group be consulted on the Platero pilot project.

"In accordance with Colombian regulations we expect this second ruling to come more or less in the first week of June," Catalina Velasquez, Ecopetrol's external affairs manager, told Reuters on the sidelines of a discussion about fracking pilot projects.

If the pilot projects lead to commercial fracking, Ecopetrol could develop 150 to 200 fracking wells in the Magdalena Medio region, the company's vice president of non-conventional energy deposits Gabriel Combariza, told journalists.

Characteristics observed by Ecopetrol in the region suggest that "these wells are going to produce more or less 1.1 million to 1.2 million barrels each (of oil equivalent) in their working life," Combariza said, adding each well could operate for between 20 and 25 years.

"We are talking about extending the reserves horizon by between 12 and 15 years," he added.