The calculation of a 15% drop since the start of last year came from the annual economic impact report of trade body Oil and Gas UK.
It said the number of jobs supported by direct, supply chain and indirect employment had fallen from 440,000 to 375,000.
The cuts came as operating expenditure on existing assets was slashed.
About £800m (8%) of costs have been cut this year and a further £1.3bn (14%) is planned for next year. The report said cost-cutting could be expected to be the focus of industry activity for the first nine months of this reaction to lower prices.
The industry is responding to revenues falling by 20% last year, and another 30% this year.