Select copper, zinc and nickel prices declined at the non-ferrous metal market today due to stockist selling amid weak demand from industrial users. Copper sheet cuttings and brass utensils scrap were marginal up, owing to good demand from consuming industries. Nickel prices slid by Rs 5 per kg to Rs 920 from Wednesday's closing level of Rs 925 and copper armiture eased by Rs 3 per kg to Rs 439 from Rs 442.