HONG KONG (Reuters) - Aviva plc is putting its South Korean and Sri Lankan businesses on the auction block, sources with knowledge of the matter said, adding to the insurer's list of Asia divisions it is selling as part of a global plan to raise money to protect against its euro zone exposure. Britain's second-biggest insurer laid out plans last week to sell underperforming businesses around the world, a move meant to address the company's greater exposure to the troubled euro zone compared with rivals, and to boost a share price that is down more than 36 percent in the past year. ...