BEIJING, May 31 (Reuters) - Copper prices drifted lower on Wednesday and were set for a second consecutive monthly drop, as weaker-than-expected manufacturing data from top consumer China and lacklustre global economic performance dampened demand outlook.

Three-month copper on the London Metal Exchange was down 0.6% at $8,078.50 a tonne by 0749 GMT.

The official manufacturing purchasing managers' index (PMI) fell to a five-month low of 48.8 from 49.2 in April, according to data from the National Bureau of Statistics.

The PMI was below the 50-point mark that separates expansion from contraction, and also lagged a forecast of 49.4.

The data further dampened market sentiment, which was weighed down earlier by a set of economic data showing dismal economic recovery momentum in the world's top metal consumer, including a slump in the country's industrial profit.

Such a patchy recovery buoyed hopes for more policy support in China, Guangda Futures said in a note, adding that demand in the world's top consumer declined in May as end-users' demand remained subdued.

Globally, jitters around the U.S. debt ceiling negotiation and economic outlook also muted investors' risk sentiment.

The contract has lost 6% so far this month and was set for the biggest monthly drop since June 2022.

The most-traded July copper contract on the Shanghai Futures Exchange was little moved at 64,920 yuan ($9,133.23) a tonne, having lost 2.8% so far this month.

The price drop propelled buying in spot market, pushing up premiums against tight stocks in the market.

The spot copper premium assessed by Shanghai Metals Market hit a five-month high at 425 yuan a tonne last week and stood at 375 yuan on Tuesday.

LME aluminium was unchanged at $2,223 a tonne, tin eased 0.2% to $25,500, zinc declined 1.2% to $2,274.50, lead shed 0.7% to $2,049, and nickel dropped 2.1% to $20,585.

SHFE aluminium added 0.4% to 18,015 yuan a tonne, zinc slid 0.5% to 19,240 yuan, lead nudged 0.2% lower to 15,195 yuan, nickel fell 4.8% to 156,100 yuan, and tin slipped 1.4% at 206,450 yuan.

For the top stories in metals and other news, click or ($1 = 7.1081 Chinese yuan renminbi) (Reporting by Siyi Liu and Dominique Patton; Editing by Sherry Jacob-Phillips and Varun H K)