Oil and gas production in the North Sea has risen by more than 10%, the first increase in 15 years.

Trade body Oil and Gas UK said operating costs have fallen by around 45% due to industry cutbacks.

About 120,000 jobs have been lost over the last two years and investment in the sector has slumped.

Oil and Gas UK's 2016 Economic Report said well-based activities had seen revenues fall 53% since 2014.

Earlier this month, Scottish Government statistics showed companies were extracting more oil and gas in an attempt to make up for the loss.

High supply and low demand saw the price of a barrel of Brent crude plunge as low as $26 in January. It later climbed to $50 and now sits at around $45, about a third of its price two years ago.

The 10.4% increase in production in 2015 followed a years-long decline in the UK Continental Shelf (UKCS) and activity remains far lower than in the late 1990s and early 2000s.

The boost in production was largely accounted for by 12 new fields starting production and work restarting on seven others.

Oil & Gas UK chief executive Deirdre Michie said: "The UKCS is in urgent need of fresh investment to boost exploration and drive activity, particularly for the supply chain.

"Exploration has fallen to record lows and little new investment has been approved in 2016 and 2017 looks no better. Increased asset trading is one area that could free up new investment by facilitating the trading of late-life assets.

"In light of this I am calling on governments today to vigorously champion the UK's oil and gas industry, by providing certainty in our fiscal regime, encouraging new entrants to the market and recognising our supply chain as vitally important to the economy.

"The evidence in the report demonstrates what our industry can achieve when the basin's competitiveness is addressed and the tax regime reformed.

"Now it is time for the UK and Scottish Governments to reinforce their efforts to promote the UKCS, nationally and internationally, as an attractive investment with world leading capability from front end exploration to late life operations."

The SNP welcomed the reported efficiency savings but said the UK Government must do more to bolster the industry amid low oil global prices.

The party's energy spokesman Callum McCaig MP said: "Oil and Gas UK's latest economic report lays down a serious challenge to the UK government.

"The industry has worked hard towards lowering costs and continued collaboration will only help to improve the picture. Production rates are healthy too, but with global oil price remaining suppressed these measures do not go far enough.

"In the SNP we have long called for serious, sensible measures which will make a real difference in incentivising exploration and development of new prospects in the North Sea. With these latest figures showing record low activity in exploration, the time for action from the UK government to boost activity and protect jobs is long overdue."

He continued: "Let's bear in mind the North Sea oil and gas sector has generated £300bn for the Treasury and has now been abandoned by the Tories in its time of need.

"If Theresa May's government doesn't now focus on vital support for the sector, to see through the worst of the downturn and encouraging future growth, then they will be guilty of perpetrating one of the most shameful betrayals in the history of Scottish industry."

UK Government minister Andrew Dunlop said: "The oil and gas industry has seen significant changes over the past few years, and today's report by Oil and Gas UK shows that there continues to be challenges.

"The UK Government is committed to supporting our oil and gas sector, and the jobs which depend on it. That's why in the last two years we have put in place tax breaks worth £2.3 billion, strengthening the North Sea's appeal to international investors as a global centre of excellence.

"While the industry is adapting to this new business environment, there are opportunities that can be seized. Production outputs are higher and there has been a significant reduction in operating costs. There's a determination in the sector to make a success of this new trend and create a lasting legacy for an industry that makes a huge contribution to Scotland and the UK."