Osborne announced Friday that as much as $397 million in profits generated from mature oil and natural gas fields in the North Sea would be protected from a supplementary tax charge.
Osborne was quoted by the BBC as saying the tax relief would provide a major incentive for operators to get all of the resources they can out of aging North Sea fields.
"This government has signaled its absolute determination to get more investment in the North Sea, a huge national asset," he said.
The level of tax relief would depend on the size of the operation. Industry officials told the BBC the measure could generate as much as $3 billion in new investments.
Energy companies working in British territories expressed frustration when the government raised taxes on oil and natural production last year.
"Today's tax allowance is more good news for the North Sea, good news for jobs and good news for the broader economy," Osborne said.
Mike Tholen, an economic director at Oil and Gas U.K., told the BBC that, with the right investments, "we're looking at another 50 years activity still in this basin."