Definition: In this task, you are given a news article. Your task is to classify the article to one out of the four topics 'World', 'Sports', 'Business', 'Sci/Tech' if the article's main topic is relevant to the world, sports, business, and science/technology, correspondingly. If you are not sure about the topic, choose the closest option. Note that URLs in the text have been replaced with [Link].
Input: 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 

Business