Oil prices fell on Monday after Aramco chief Amin Nasser warned that low investment in the industry could lead to a supply shortage.

The oil industry has lacked investment of late as money is poured into the development of alternative energy sources. However, Nasser said it was ‘premature’ to assume that shale oil and alternative energy resources can be developed quickly to replace oil and gas”

“New discoveries are also on a major downward trend. The volume of conventional oil discovered around the world over the past four years has more than halved compared with the previous four,” Nasser said.

WTI Crude is currently down 0.88 percent at $43.84, with Brent Crude down 0.77 percent at $46.35 (1046GMT).