METALS-Copper edges higher for third day on China's stimulus measures

London copper prices crept forward for a third straight session on Thursday as China's move to inject liquidity into the financial system boosted expectations of higher demand in the world's top industrial metals consumer. The People's Bank of China is injecting 250 billion yuan ($37 billion) through seven-day reverse bond repurchase agreements and 150 billion yuan through 28-day reverse repos,