(Adds analyst comment, updates prices) BEIJING, April 2 (Reuters) - Shanghai base metal prices made a positive start to the second quarter on Monday as the dollar slipped, making metals cheaper for holders of other currencies and supporting prices. "The second quarter should be not bad," said Xu Maili, director of non-ferrous metal research at Everbright Futures in Shanghai, noting that the April-June period was the peak season for metals consumption. Of the five key Shanghai base metals, only nickel rose in the first quarter, while copper and aluminum posted double-digit losses. The London Metal Exchange remains closed on Monday for the Easter holiday.
* SHFE COPPER: The most-traded May copper contract on the Shanghai Futures Exchange percent climbed 0.5 percent to 50,240 yuan ($8,001.66) a tonne by the mid-session interval. Earlier in the session, it touched 50,600 yuan a tonne, its highest since March 23.
* ALUMINIUM: ShFE aluminum rose 1.4 percent to 13,920 yuan a tonne, bouncing back from a 17-month low seen on Friday.
* ALUMINIUM: China has slapped extra tariffs of up to 25 percent on 128 U.S. products including scrap aluminum, in response to U.S. duties on imports of aluminum and steel, China's finance ministry said.
* USD: The dollar index, which measures the greenback against a basket of six other major currencies, was down 0.2 percent at 89.98.
* NICKEL: Shanghai nickel was the biggest gainer in the base metals complex, rising 1.6 percent to 100,500 yuan a tonne, tracking a rise in the ferrous metals complex. Nickel is used to make stainless steel.
* COPPER: China's top copper smelters on Friday cut their minimum treatment and refining charges for copper concentrate by 10.3 percent for the second quarter of 2018, two people with direct knowledge of the matter said. For the top stories in metals and other news, click or
* Asian stocks began the new quarter on Monday with mild gains following a strong performance by global equities last week.
BASE METALS PRICES 0432 GMT Most active ShFE copper 50230 Most active ShFE aluminum 13915 Most active ShFE zinc 24995 Most active ShFE lead 18825 Most active ShFE nickel 100480 Most active ShFE tin 145540
($1 6.2787 Chinese yuan)
(Reporting by Tom Daly Editing by Aaron Sheldrick and Amrutha Gayathri)