Mexican billionaire Carlos Slim doubled his investment stake in the New York Times Co. to about 17 percent, making him the biggest owner of the parent of the New York Times.

The 74-year-old Slim exercised warrants purchased in 2009, which helped the media company survive the global financial collapse.

He has maintained a passive ownership position and promises to continue to do so.

"We continue to have confidence in the management, we think they're doing things well," he said in a statement that called the Times "a valuable brand."

NYTC CEO Mark Thompson said Slim's increased investment is "in the best interests of the company." This "one-off purchase program should not be viewed as a change of position in our capital allocation plans."

Slim controls the biggest telecommunications company in Latin America and has interests in mining, banking, construction, real estate and auto parts.