Venezuela extended a suspension of foreign exchange trading for another week and said it was studying a fixed exchange rate to offset an eight-week opposition strike that has slashed vital oil income.

"The suspension that was scheduled to be lifted... will be prolonged for one week precisely so we can fine tune this process, until Wednesday, February 5," Finance Minister Tobias Nobrega told local television in an interview on Monday night.

Nobrega said the government was considering a single fixed exchange rate as part of measures to halt the slide in its bolivar currency and shore up its international reserves during the strike, which aims to force President Hugo Chavez to resign.

The minister said the government was still studying whether to introduce one exchange rate adjustable over time or a dual exchange rate system. No decision has been made on where the exchange rates would be set, he said.

"The government is considering working in a first stage with a strong integral control because we are losing international reserves dramatically, we are losing about $60 million a day," Nobrega said in the interview. "In the first stage, there would be just one exchange rate administered by the Central Bank."

Venezuela's government last week suspended foreign exchange trading for five market days as it rushed to preserve the hard currency reserves of the world's fifth-largest oil exporter. Reserves have dipped since the opposition strike began and stood at $11.05 billion by January 24.

The government was studying various proposals on how to implement the measures and officials were speaking with banks on what exchange rate would work under the new controls, government and banking sources told Reuters.

The opposition strike, started on December 2 to force Chavez to call immediate elections, has driven Venezuela's economy deeper into recession and sent the bolivar tumbling against the US dollar by about 28 per cent since the shutdown began.

The bolivar has fallen more than 24 per cent since the start of the year, after losing about 46 per cent of its value against the US dollar last year amid growing investor jitters over the nation's economic and political stability.

Opposition leaders say Chavez has driven Venezuela into economic and political turmoil with his populist reforms and dictatorial style. They are pressing the president to agree to early elections and say they will maintain their strike until he resigns or calls a vote.

But the former paratrooper, who was elected in 1998 and survived a coup in April, has refused. He brands his foes as rich elites determined to topple him by destroying the oil sector, which provides half of government revenues.