Libya's lifeline oil and gas exports raised revenues of more than $21.5 billion in 2021, the highest level in five years, the National Oil Corporation announced Saturday.

Total net revenues for oil and gas exports last year amounted to $21.5 billion as well as 30 million euros in non-dollar sales, the state-run NOC said in a statement.

It said record levels were achieved in November and December, raising a combined $4.3 billion in the two last months of 2021.

"The end of the year 2021 recorded a recovery, and oil prices achieved their largest annual gains since 2016, driven by the recovery of the global economy from the state of stagnation" due to the coronavirus epidemic, NOC chief Mustafa Sanalla said.

Since the 1970s, Libya which sits on the largest known oil reserves in Africa has been heavily dependent on revenues from its hydrocarbon exports.

But in a decade of violence since the 2011 revolt that overthrew and killed dictator Moamer Kadhafi, armed groups have frequently blockaded or damaged oil installations.

The shutdowns have forced the NOC to declare force majeure, a legal move allowing it to free itself from contractual obligations in light of factors beyond its control.

Oil production has recovered to 1.2 million barrels per day, as opposed to between 1.5 million and 1.6 million bpd before the NATO-backed uprising of 2011.

But Sanalla warned "the ability of the oil sector in Libya to invest and advance the process of infrastructure modernisation will remain weak in the foreseeable future, especially in light of the scarcity of budgets".

"What we need more than ever is to think outside the box and create initiatives to save the infrastructure," he stressed.