Oil giant BP has revealed plans to cut around 20% of its North Sea workforce, putting 600 jobs at risk.

The firm plans to shed 4000 more jobs globally as a result of the downturn, which has already put thousands out of work in the last two years.

BP's North Sea operations employ 3000 people, including 1250 in Aberdeen, 565 offshore, 350 in Shetland, 330 in Grangemouth, 150 in London and 250 in South Korea. The firm cut 300 North Sea jobs last year.

A BP spokesman said: "We are committed to the North Sea and see a long-term future for our business here.

"For example, in 2016 we are continuing to invest around $2bn of capital into North Sea projects and a further $2bn in running our North Sea operations.

"This will sustain many hundreds of jobs, both in BP North Sea and our supply chain going forward.

"However, in toughening market conditions and given the well-documented challenges of operating in this maturing region, we need to take specific steps to ensure our business remains competitive and robust.

"An inevitable outcome of this will be an impact on headcount and we expect a reduction of around 600 staff and agency contractor roles by the end of 2017, with the majority of these taking place this year.

"We are speaking to our staff and agency contractor management and will work with those affected over the coming months."

At least 65,000 people have lost their jobs in the UK since the value of a barrel of oil halved from a high of $110 in June 2014.

Industry body Oil and Gas UK recently predicted that UK hydrocarbon production increased by 7% over the course of 2015, the first rise in 15 years.

But experts warned further cuts are likely as the sector continues to face tough times.

Aberdeen City Council leader Jenny Laing added: "This is very disappointing news and a sign of the continued difficulties facing the sector but we welcome the commitment from BP that the company still sees a long-term future in this area and is continuing to invest heavily in the North Sea."

Speaking at a press briefing in Edinburgh, First Minister Nicola Sturgeon said: "We are reminded again today that this is a very difficult time indeed for people working in the North Sea.

"For anybody who is faced with losing their job that, of course, is a crisis and for any company that is faced with making redundancies then obviously that is the case. I think it is also important, though, to note and indeed to welcome BP's continued commitment to the North Sea.

"BP has reiterated today its investment plans both in capital investment and operational investment in the North Sea this year and has said that it sees a long-term future for its business in the North Sea.

"Nevertheless, this news today is difficult news and we will be engaging closely with BP to understand in more detail the announcement that they've made.

"I will also, as I have been doing over the past year, make sure that the task force that I established round about this time last year is focused on doing everything that we practically can do to help both individuals who are facing the prospect of redundancy but also helping the industry in general as it seeks to cope with what are very difficult market conditions."

Scottish secretary David Mundell said: "The UK Government will work with the Scottish Government to ensure help is provided to those affected, including through the Job Centre Plus network."