HONG KONG — China’s manufacturing sector contracted in July at the quickest pace since last summer, according to the early reading of a survey released on Wednesday.

The survey came in at an 11-month low of 47.7 points for July, down from the final June figure of 48.2. A result below the 50-point level signals contraction.

The monthly survey of purchasing managers in the manufacturing sector, compiled by the research firm Markit and released by the British bank HSBC, offers one of the earliest glimpses at how the economy is doing each month and is closely watched by economists and investors. Final figures for July, based on more complete survey results, are scheduled to be released next week, alongside the results of an official manufacturing survey to be published the National Bureau of Statistics.

The so-called flash P.M.I. data provided the latest sign of the pressures faced by China as a whole as the authorities in Beijing try to raise productivity, living standards and domestic demand while shifting the economy away from its reliance on exports and investment.