May 21 (Bloomberg) -- Venezuela, the world's fifth-largest oil exporter, said international oil companies operating in the country owe about $4 billion in back taxes and unpaid royalties.

Energy and Oil Minister Rafael Ramirez said international companies operating 32 oil fields for state oil company, Petroleos de Venezuela SA, owe about $3 billion in income taxes. Four extra-heavy oil joint ventures owe an additional $1 billion in royalties, Ramirez said. Ramirez has said the companies owe taxes but until today never provided an estimate of the amount.

``We don't want foreign companies to leave the country,'' Ramirez said at a press conference today. ``But companies have to obey the laws.''