BHP Billiton leads London on bigger share buyback LONDON (CBS.MW) -- Anglo-Aussie miner BHP Billiton (BHP) (UK:BLT) climbed 2.8 percent to lead FTSE 100 components after it increased its share buyback to A\$2.27 billion (US\$1.78 billion) from the A\$1 billion to A\$1.5 billion it had predicted it would buy 