Nigeria LNG Ltd's plant is producing at up to 68% of its capacity due to theft of crude oil and vandalism of pipelines, among other problems, head of the company said on Tuesday.

Nigeria LNG is a consortium between state-run Nigerian National Petroleum Corporation, Eni, TotalEnergies and Shell with a capacity of 22 million tonnes per year.

Chief Executive Philip Mshelbila said theft and vandalism were gradually strangulating Nigeria's oil and gas sector.

"We have been producing in the last month at about between 60 to 68 percent utilisation. In other words, roughly 35% of our capacity is empty," he told an energy conference in Abuja.

"There are many factors, but the biggest one of them is crude oil theft. If we don't address this, we will not get out of this quagmire that we're in."

Mshelbila said his company had stopped exports of liquefied petroleum gas for domestic use to meet demand from the local market.

Nigeria's petroleum regulator said last week the country lost $1 billion in revenue during the first quarter of this year due to crude oil theft, warning the practise was a threat to the economy of Africa's top producer.