Australia's Woodside Petroleum said after the markets closed Wednesday that it agreed to acquire Senegal assets owned by ConocoPhillips (COP - Get Report) for $350 million plus a completion adjustment of around $80 million.

The deal includes all of the shares of ConocoPhillips Senegal BV, which holds a 35% working interest in a production sharing contract with the Senegal government covering exploration blocks Rufisque Offshore, Sangomar Offshore and Sangomar Deep Offshore. The acquisition includes the option for Woodside to operate the future development of any resource.

The contract includes the SNE and FAN deepwater oil discoveries. Woodside said SNE is one of the largest global deep water oil discoveries since 2014 and contains an estimated 560 million barrels of recoverable oil.

Other joint venture participants include operator Cairn Energy (40%), Far (15%) and Senegal's national oil company, Societe des Petroles du Senegal, or Petrosen (10%).

The assets had a net carrying value of around $250 million on May 31, according to Houston-based ConocoPhillips a separate statement. "This is an important milestone for ConocoPhillips as we progress our phased exit from deepwater exploration in West Africa," Matt Fox, executive vice president of strategy for exploration and technology, said.

Guy Baber, an analyst at Piper Jaffray's Simmons & Co. International, said in a note Thursday that ConocoPhillips' ability to sell the blocks in a difficult asset sales market for about $2 per barrel of oil equivalent P90 (meaning 90% certainty of being produced) is positive on the margin given the cash inflow and the company's shift away from deepwater exploration.

Analysts at Tudor, Pickering, Holt said the $2.20 per barrel valuation -- which is lower than most companies' finding costs -- adds to the trend of weak valuations for international conventional oil discoveries but noted that the price surpasses the $215 million they thought the assets were worth. They said the field should be commercial at more than $50 per barrel.

Simmons has a neutral rating on ConocoPhillips' stock with a $44 price target while TPH has a hold rating and a $42.87 price target.

Woodside CEO Peter Coleman said in a statement that the acquisition aligns with the company's growth strategy by providing a significant position in an under-explored and highly prospective emerging oil province, noting that recently completed appraisal work has proved up high-quality resources.

"We are taking advantage of our balance sheet to acquire a world-class asset that fits well with our capabilities, offers significant future upside in exploration and line-of-sight to near term oil production," he said.

Coleman said the deal builds on its agreement to acquire a 65% interest in the AGC Profond exploration block located to the south in the Senegal-Guinea Bissau joint development zone and extends its regional focus in West Africa. He said the company will bring its experience in deepwater drilling, development and operation of subsea infrastructure and floating production storage and offloading vessels to the joint venture.

The deal has to clear the Senegal government but is expected to close by year-end.