BEIJING--A preliminary gauge of Chinese manufacturing activity rose to an 18-month high in July, suggesting Beijing's efforts to stimulate growth are paying off.

The preliminary HSBC China Manufacturing Purchasing Managers' Index, a gauge of nationwide manufacturing activity, rose to 52.0, compared with a final reading of 50.7 in June, HSBC Holdings PLC said Thursday.

A reading above 50 indicates expansion from the previous month, while a reading below 50 indicates contraction.

China posted output growth of 7.4% in the first quarter compared with a year ago and 7.5% in the second, a slowdown from the 7.7% growth the world's No. 2 economy posted in the fourth quarter of 2013. China has responded with a series of steps that include speeding up construction projects and picking up the pace of lending, which economists have called ministimulus measures.

"Economic activity continues to improve in July, suggesting that the cumulative impact of ministimulus measures introduced earlier is still filtering through," HSBC economist Qu Hongbin said in a statement.

Exports also improved, suggesting stronger global appetite for the goods China's factories make.

New export orders expanded at a faster pace in July than a month earlier, and the employment and prices subindexes also improved, according to HSBC.

The preliminary PMI figure, also called the HSBC flash China PMI, is based on 85% to 90% of total responses to HSBC's PMI survey each month, and is issued about one week before the final PMI reading.

Grace Zhu