PRECIOUS-Gold and silver extend losses, struggle near 4-yr lows

(Adds comments, Chinese premiums and drop in mining stocks) By A. Ananthalakshmi SINGAPORE, Nov 3 (Reuters) - Gold and silver extended their losing streak to a fourth session on Monday to trade near their lowest in more than four years, with a stronger U.S. dollar and possible technical selling likely to keep them under pressure. Precious metals took a beating on Friday after the Bank of Japan's surprise decision to boost its already huge bond-buying stimulus prompted the yen to fall