Anglo American, BHP Billiton and Xstrata confirmed to Colombian President Juan Manuel Santos their plans to invest $1.3 billion to expand the Cerrejon coal mine.

The investment program was ratified by senior executives of the three global mining giants during a meeting here Thursday with Santos at the presidential palace.

The multinational firms had initially announced their plans to expand Cerrejon, which is located in northern Colombia and considered the world's largest open-pit coal mine, during a gathering in Melbourne, Australia, BHP Billiton's headquarters.

The project includes expanding port and transport infrastructure and will enable Cerrejon's annual production - which is destined for export - to increase from 32 million tons to 40 million tons.

In addition to the 25 percent increase in output, the project will create 5,000 additional jobs and boost to 350 billion pesos ($179.62 million) the amount of royalties the country will receive, Santos said.

"It's a sign of confidence in our country," Santos said in a joint statement to reporters after the meeting.

Leon Teicher, the president of the Xstrata subsidiary that operates the mine, echoed the president's remarks and noted that "Cerrejon is a Colombian company with foreign capital, a company that with 10,000 employees at present only has four people who do not have Colombian nationality."

Cerrejon is managed by the Carbones del Cerrejon company, a joint venture in which the three multinationals have equal 33 percent stakes.