By Shashwat Awasthi and Yadarisa Shabong
(Reuters) - An unexpected slowdown in China's April factory activity coupled with a firmer pound weighed on the FTSE 100 as miners and exporters weakened, even as Standard Chartered (LON:STAN) surged on buyback plans.
Dim outlooks from Glencore (LON:GLEN) and Whitbread (LON:WTB) added to woes as the main index closed down 0.3 percent. The FTSE 100 nevertheless managed to clock in a fourth consecutive month of gains.
The domestically focused FTSE 250 lost 0.4 percent on Tuesday.
Glencore dropped 2.6 percent as severe flooding in Australia led it to lower its 2019 copper output target.
Whitbread, the owner of Premier Inn, fell 6.2 percent on its worst day in more than two years after forecasting weak room revenue growth in the UK.
Mining shares were at over a month-low, hit as most industrial metals weakened. Data showed factory activity in China, the world's biggest copper consumer, unexpectedly slowed in April.
"Chinese recovery may well take longer than expected, and it is premature to hang out the bunting for a Chinese-led global recovery in economic activity over the rest of the year," CMC Markets analyst Michael Hewson said.
But that didn't deter Asia-exposed Standard Chartered. The bank's London-listed shares jumped 4.6 percent to a 10-month high after it announced plans for a share buyback of up to $1 billion, its first such in at least 20 years, and posted higher earnings.
The pound ultimately decided the FTSE 100's fate on Tuesday, however, rising on media reports that the tone of cross-party Brexit talks had improved.
AstraZeneca was the biggest drag on the index.
Packaging firm DS Smith's shares slipped 4.2 percent after a full-year update. "There were no fireworks in the pre-close," Jefferies analysts noted.
The mid-cap index also booked monthly gains but Sirius Minerals slumped on its worst day in nearly 2-1/2 years, losing 20.5 percent after a discounted share offering.
Pub-operator Greene King (LON:GNK) shed 7.5 percent, its biggest one-day fall since late June, despite forecasting annual pre-tax profit above analysts' expectations.
"Although this is a good result, we think it will have largely been priced in given the weak comparable and the favourable Easter weather," JP Morgan analysts wrote of Greene King update.