LONDON, May 2 (Reuters) – Copper and nickel bounced off multi-week lows on Wednesday as Chinese steel prices soared, a dollar rally paused and a private survey showed growth in China’s manufacturing sector unexpectedly picked up in April. The Caixin/Markit Manufacturing Purchasing Managers’ index (PMI) climbed to 51.1, from a four-month low of 51.0 in March, and topped economists’ forecast for a modest slowdown to 50.9. But the same survey showed a sub-index on export orders shrinking for the first time since November 2016. An official PMI survey on Monday also showed slower shipment orders last month. “The PMI (data) doesn’t bode well for activity in the coming months,” said Caroline Bain, senior commodities economist at Capital Economics. “We’re not expecting metals to fall off a cliff, we just think they could drift lower in the second half. There’s a risk we’ve peaked with the global economy.” COPPER, NICKEL: Three-month copper on the London Metal Exchange rose 1.1 percent to $6,817 per tonne by 1035 GMT, after hitting $6,710 on Tuesday, its weakest since April 4. Nickel rose 2.1 percent to $13,945, after hitting its lowest since April 12 on Tuesday. CHINA STEEL: China’s steel rebar futures soared to their highest in eight weeks, buoyed by a firm physical market that helped run down inventories amid supply constraints. GLOBAL MARKETS: World stocks inched higher after two days of losses but remained pinned down by the dollar’s recent surge and expectations that a U.S. Federal Reserve meeting later in the day will signal further policy tightening. U.S. TRADE RESTRICTIONS: U.S. officials are pushing for quotas and “other restrictions” on steel and aluminium imports, a top trade official said. RUSAL: The U.S. Treasury gave investors an additional month to divest or transfer their holdings in sanctions targets En+ Group Plc, GAZ Group and United Company Rusal Plc, Russia’s largest aluminium producer. RIO TINTO: The U.S. Treasury’s move may greatly reduce restrictions on Rusal, Rio Tinto said. ALUMINIUM: Aluminium eased 0.1 percent to $2,257 a tonne. Prices hit a seven-year peak of $2,718 on April 19 after the United States imposed sanctions on Rusal. ALUMINIUM STOCKS: LME data showed on-warrant or available aluminium stocks have fallen to 880,350 tonnes, close to the 836,175 tonnes hit in January, which was the lowest number since 2007.