Tullow Oil has entered an agreement to acquire Norwegian exploration company Spring Energy for $372.3 million, and also announced it intends to dispose of its UK and Dutch gas assets.

In addition to the $372.3 million purchase price, Tullow has also agreed to a bonus payment in the event of a commercial discovery.

The payment is limited to four specific prospects in Spring’s current drill queue and will be paid on a sliding scale of up to $150 million per prospect and $300 million in aggregate.

Tullow did not list which prospects the bonus payments related to but Spring currently has up to 16 exploration wells planned over the next 24 months, three of which it is the operator of.

Spring holds 28 offshore licences,including five as operator, covering 18,000 square kilometres across the Norwegian Continental Shelf.

The company also applied for new licences in Norway’s 22nd licence round earlier this year.

Tullow said it had assessed Spring’s existing exploration portfolio to contain more than 230 million barrels of oil equivalent of risked prospective resources and noted the company currently has 24 million boe of existing reserves and resources.

Tullow will keep on Spring’s 37 Oslo-based staff who will form the basis Tullow Norge which will be headed by Spring’s current chief executive Roar Tessem.

Spring is majority owned by Norwegian private equity company HitecVision which made an initial investment in the company in 2008 followed by additional investments to help fund its growth.

The sale comes the same week HitecVision sold off the businesses making up its SPG unit for a combined Nkr1.3 billion ($229.2 million).

The Spring deal will have an effective purchase date of 1 September 2012, however it is still subject to approval from the Norwegian Ministries of Energy and Finance.

Tullow also announced on Tuesday that it was planning to offload its UK and Dutch gas assets as part of its ongoing strategy to manage its portfolio and monetise non-core assets.

“These transactions are part of an ongoing process of carefully refocusing our business and ensuring efficient allocation of capital by monetising non-core assets and re-investing the proceeds in high potential oil exploration,” said Tullow chief executive Aidan Heavey.

“Our Southern North Sea gas assets are therefore no longer core to Tullow’s business which has a clear focus on light oil in Africa and the Atlantic Margins.

“The acquisition of Spring adds a material portfolio of oil exploration assets and high quality people that will provide a superb foundation for building our portfolio and expertise in the highly prospective North Atlantic.”

Its assets in the UK and Dutch Southern North Sea currently produce about 18,000 barrels of oil equivalent per day and the company hopes to complete their sale by the end of next year.