Renjifo, who also is a board member at state oil company Ecopetrol, will replace Mauricio Cardenas, who will become finance minister.

He takes the reins of the energy sector at a crucial time for the South American nation.

Over the past decade, improvement in its security situation has led to record foreign investment both in its coal mining and oil extraction sectors.

Colombia ranks as one of the world’s top coal exporters.

That sector was blighted by a strike that brought rail transport of coal to a halt.

The strike has since been resolved.

Colombia also is South America’s fourth largest oil producer.

However, the oil boom has stalled with output declining over the past three months as security has deteriorated.

Attacks by leftist guerrillas on oil pipelines and infrastructure has been rising sharply.

There also have been complaints from private oil producers that the approvals process takes too long, slowing their efforts to ramp up production.

No tears for Argentina from Colombia

In other Colombia news, the country has overtaken Argentina to claim the mantle of the third largest economy in South America.

At least that is the view of outgoing finance minister Juan Carlos Echeverry.

However, there is some dispute over the accuracy of the figures Echeverry is using to back up his claim.

Colombia Reports cites Echeverry as saying Colombia’s gross domestic product outgrew that of both Venezuela and Argentina in the two years since President Juan Manuel Santos took office.

In an interview with newspaper El Tiempo, Echeverry said Colombia’s GDP was expected to grow to $US363 billion, while Argentia’s GDP was expected to reach $347 million.

According to the World Bank, Colombia’s GDP was $322 billion in 2011, while Argentina’s was $446 billion.

Colombia Reports quotes the Financial Times, as saying Echeverry was not applying the official currency rate of the Argentine peso of 4.65 to the US dollar, but rather the black market rate that had grown to 6.37/dollar.