BHP Billiton's planned exit from the US Lower 48 flies in the face of industry trends. Operators that have built prime growth portfolios in unconventionals tight oil in particular but gas too are the envy of the have nots . The haves like BHP Billiton typically look to high grade and expand taking advantage of economies of scale and technological know how. Besides being prompted by activist investor Elliott Advisors BHP Billiton s motivation to sell is driven by a need for greater focus across its diversified commodities business and a desire to realise value from assets which would be more highly prized by others. The US Lower 48 currently represents less than 10% of the conglomerate s entire Enterprise Value.