An oil exploration firm set up out of Norwich is to be bought in a deal worth �14.3m.

Nio Petroleum (Sabah), set up by two former managers at oil services and production firm Petrofac, is being bought by EnQuest, based in Aberdeen.

The firm was set up in 2010 by Richard Hall, who previously worked with Norwich-based Acteon before moving to Petrofac, and Rory Edwards, also previously at Petrofac.

It said its niche was opening up dormant discoveries and redeveloping mature, previously developed fields and was working in partnership with Malaysian state firm Petronas and Sweden's Lundin on two blocks of the coast of Sabah, Borneo.

Mr Hall, said in 2010 that they were also looking to Vietnam and had hoped in about three to four years to float the firm on a stock market.

Both Mr Hall and Mr Edwards were replaced as the directors of Nio Petroleum (Sabah) last month.

The firm's parent company, Nio Petroleum, set up from a Norwich address in 2009, with backing from Barclays Natural Resource Investments, a division of the investment bank, is not thought to be part of the deal.

It describes itself as providing administrative support to its subsidiaries and posted loses of �813,000 in 2011.

Nio Petroleum (Sabah)'s assets include an appraisal opportunity at the Bambazon oil discovery as well as other exploration targets, said EnQuest.

EnQuest was formed from the demerged UK North Sea assets of Petrofac and Lundin Petroleum in April 2010.