One of the world's richest men says instead of the current model of a 40-hour workweek and retirement in the 60s, the world should adopt a system of working later in life with more time off.

Mexican magnate Carlos Slim Helu of telecom giant América Móvil told a business conference in Uruguay this weekend he thinks the world needs a "radical change" in the way we approach our working lives.

"This means that people do not retire at 50 or 60 years old," news agency Paraguay.com reported him as saying at the 20th Montevideo Circle meeting, an annual meeting of business leaders and politicians from across Latin America. "People will have to work longer, to 70 or 75 years old, and only work three days a week."

The catch is that sometimes, employees may need and want to work much longer and harder on days when they do work — possibly as much as 11 hours a day, he says.

Slim, a self-made billionaire who has cornered the Mexican telecom market, says the concept of retirement comes from the Industrial Revolution, when life expectancy was until 60 to 75 years old. Now, people in the developed world regularly live to 86, 90 or beyond.

As founder of Telmex, Slim is also putting his money where his mouth is. His telecom conglomerate recently offered a deal to employees whereby long-serving workers can sign up to work well past the traditional retirement age, but on a reduced workload of four days a week.

Slim also says the way we educate young, future workers also needs an overhaul. Education needs to be "not boring [and] memorized, but .. to train and educate. "

"We must train welders, nurses, health technicians, we need to train for jobs," he said, "giving greater importance than ever before towards educating for work.​"