By Ian Walker 



  Cairn Energy PLC said Monday that it is selling its 40% interest in the Rufisque, Sangomar and Sangomar Deep project in Senegal to Woodside Petroleum Ltd. for up to $400 million. 


  Cairn said the sale followed Woodside's confirmation that it would exercise its pre-emption rights over the project. Cairn had initially agreed to sell the project to Lukoil PJSC, subject to Woodside not exercising its option. 


  The sale is conditional upon consent from the Government of Senegal and shareholder approval. 


  The company plans to publish a circular to shareholders Monday, and the deal is expected to complete in the fourth quarter of this year. 


  Write to Ian Walker at ian.walker@wsj.com