Mexican billionaire Carlos Slim is suggesting that workers shift to a three-day work week. The catch: He would require 11-hour work days and workers to stay on the job until age 70 or 75. The Financial Times reported that in a speech at a conference in Paraguay, Slim advocated a radical change in the typical five-day work week. "People are going to have to work for more years, until they are 70 or 75, and just work three days a week -- perhaps 11 hours a day," the paper quotes him as saying. The paper said that workers at Telmex, the telecom company that has made him the world's second richest man by some estimates, now can retire before they are 50 years old in some cases. But it reported that those eligible for such early retirement are given the option of a four-day work week at full pay upon reaching retirement age.