Anadarko Petroleum this week paved the way for talks with Occidental Petroleum over a $57 billion takeover bid that could usurp the former’s recent $50 billion merger agreement with Chevron.

Houston-based Anadarko’s decision to pursue talks with city neighbour Oxy came the day before the latter revealed it has secured financial backing to the tune of $10 billion from Warren Buffett’s Berkshire Hathaway should its proposal ultimately be chosen ahead of Chevron’s earlier offer.