Gold increased on Monday rallying towards the strongest level in nearly six weeks amid signs that demand of holdings for exchange-traded products backed by the precious metal rose at the fastest pace since 2011. Bullion for delivery this month gained 0.5% to $1,260.07 an ounce, the most since December 11, and was last traded at $1,255.88 as of 3:10 p.m. Singapore time.