The Ecuadorian government has threatened to take over foreign oil concessions if the companies resist growing state control of the industry.
President Rafael Correa said every day millions of dollars were going to oil companies that should go to the state.
The government has been pressing the companies to give up concessions that give them a share of oil field profits and accept service contracts instead.
Oil firms operating in Ecuador come from Spain, Brazil, China and Italy.
President Correa said during a televised address on Saturday: "Every day that passes there are millions of dollars going to these companies that should be going to the Ecuadorean state.
"I'm out of patience. We are sending a bill to Congress that would allow for the expropriation of oil fields should the companies not want to sign the new contracts.
THIS IS WHAT SOCIALISTS LIKE CORREA DO.
AND IT NEVER FAILS TO IMPOVERISH THE PEOPLE.
THE USSR, RED CHINA, CUBA, ZIMBABWE. VENEZUELA. NORTH KOREA. AND SO ON.
ADD ECUADOR TO THE LIST.
IT'S INSANE: THE ONLY THING THAT TURNED INDIA AND CHINA INTO PROSPEROUS ECONOMIES WHICH CAN FEED THEIR OWN PEOPLE AND EXPORT IS FREE ENTERPRISE.
IT WILL FAIL IN WITH CORREA ECUADOR - AND IT WILL FAIL WITH OBAMA IN THE USA TOO.
THE ONLY THING IT WILL SUCCEED IN DOING IS MAKING PEOPLE POORER, LESS FREE AND MORE DEPENDENT ON THE STATE.
WHYEN WILL THEY EVER LEARN? WHEN WILL THEY EVER LEARN?