Ineoss oil and gas arm last year made profits of £523m even as it wrote off around £120m in a failed deal.
The figures show a vast improvement from 2017s £438m operating loss, recently released figures show.
Read more: Chrysaor takes another big chunk in the North Sea with $2.7bn deal for Conoco Phillips oilfields
It came as Ineos, which is Britains largest private company, abandoned a deal for Conoco Phillipss North Sea assets.
In April the North Sea fields were sold for $2.7bn (£2.1bn) to private equity firm Chrysaor Holdings.
Ineoss subsidiary Ineos UK E&P Holdings, which focuses on North Sea oil and gas, took a £117.8m hit from a failed deal in 2018.
The charge to the companys balance sheet came after it had paid “a non-refundable deposit made to a third party in relation to a potential acquisition opportunity,” the company said.
The accounts did not identify the third party.
Ineos UK E&P made earnings before interest, tax, depreciation and amortisation (Ebitda) of £861m. In 2017 it had a negative Ebitda of £242m.
