Venezuelan President Hugo Chavez has said a US oil company has abandoned oil wells in Venezuela during his nationalization drive this year.

The multibillion-dollar operations of Venezuela's last privately run oil fields were taken over by the state oil company on May 1, Reuters reported Thursday.

However, trumpeting the nationalization of the sector, Chavez has given the companies involved until June 26 to agree with the government over whether they remain as partners in the projects.

"Due to this policy ... some companies even left. There is one Yankee company that left and left the wells abandoned," Chavez said at a political event with university students, without naming any company.

The targeted companies in projects valued above $30 billion are capable of producing 600,000 barrels per day.

All of the companies have said they were talking to the government about possibly participating in the projects. None have said they have decided to leave the projects or stop doing business in the country.

Venezuela's socialist government has now signed new agreements with almost all foreign petroleum companies.

After months of pressure from left- wing leader Hugo Chavez most foreign oil firms working there have caved in.

They have agreed to hand over a controlling stake of their oil interests to the Venezuelan state.

Venezuela remains the fourth-leading supplier of imported crude and refined petroleum products to the United States.

HRF/IS