Oil prices moved higher on Tuesday despite efforts by former U.S. president Jimmy Carter to find a solution to the political instability that has rocked Venezuela and the 51-day strike that has slashed the country's oil exports.

Carter made two proposals after holding separate meeting with the President Hugo Chavez and the strikers who want him removed from office.

One proposal would see the strikes end in exchange for the Venezuelan government amending the country's constitution and holding early elections.

Carter's other proposal calls for a referendum on Chavez's rule a vote which cannot legally happen until August, when Chavez hits the halfway point of his six-year term.

Opponents of Chavez have been trying to hold a referendum in early February, which Chavez denounced when he went to the United Nations last week.

Despite Carter's efforts, the price of March futures for West Texas Intermediate oil was up 22 cents US per barrel at $33.18 in afternoon trading on the New York Mercantile Exchange.

Oil prices had traded down earlier in the day after Venezuelan oil tanker pilots agreed to go back to work.

Chavez was first elected in 1998 and re-elected in 2000 amid promises to redistribute Venezuela's oil wealth to the poor.

Angry with Chavez's economic policies, protesters launched their strike seven weeks ago that has paralysed large sectors of Venezuela's oil-exporting economy. Economists estimate the country has lost billions of dollars. The strike has also caused a drop in the world's petroleum supply, which has pushed up the price of crude.