The £1.6 billion deal, first announced in May, hands Ithaca stakes in 10 producing fields and boosts its production by about 300% to 80,000 barrels of oil per day.
Ithaca said the transaction — payed for using bank loans and a debt finance offering — established it as the second-largest independent oil and gas producer in the UK North Sea.
It takes over as operator of four of the 10 fields – Alba, Alder, Captain and Erskine.
California-headquartered Chevron retained its non-operated 19.4% stake in the giant Clair field, west of Shetland.
Les Thomas, Ithaca’s chief executive, said about 500 Chevron employees, including 200 offshore, would transfer to Ithaca, with no redundancies expected.
Read also: Ithaca to inject small company ethos into Chevron North Sea, CEO says
Delek said today that Ithaca had signed a five-year deal with BP for the distribution and marketing of oil and gas from the newly-acquired fields.
Meanwhile, Delek remains in talks with investors regarding its plans to float Ithaca on the London Stock Exchange.
The transaction between Delek and Chevron continues the trend of North American majors selling large packages of UK assets.
ConocoPhillips recently sold its UK division to private-equity backed Chrysaor and Marathon Oil has divested its North Sea business to RockRose Energy.
Canadian firm Nexen, which owned several North Sea fields, was acquired by China’s Cnooc in 2013.
North American oil and gas firms Apache Corporation, CNR International, Suncor and ExxonMobil continue to own significant UK portfolios.