Norwegian oil and gas group Aker BP will use exploration, mergers and acquisitions to rebuild its base of untapped resources after Dec. 16's record investment decision, the company's chief executive told Reuters.

Aker BP and its partners announced plans to invest more than 200 billion NOK (US$20.3 billion) in 11 oil and gas projects off Norway in the coming years, putting a large portion of the company's resource base on track for production.

As a result, Aker BP's portfolio of undeveloped reserves will shrink to just 500 MMboe from 1.4 Bbbl, CEO Karl Johnny Hersvik said on the sidelines of a project signing ceremony.

The company now plans to rebuild its base of untapped resources.

"While we are developing these projects we will crack on with exploration and M&A," Hersvik said.

"We have had the best discovery year this year, and 2023 looks very promising," he added.

New discoveries and reserves acquired in the coming years could thus be ready for development decisions later this decade when the company's current investment plans are completed, the CEO said.

Aker BP, partly owned by BP, has become the second-largest petroleum producer off Norway after Equinor following its $14 billion acquisition of the Norwegian assets of Sweden's Lundin Energy.

Norway is Europe's largest supplier of natural gas and a major producer of oil.