French manufacturing activity picked up slightly in April, S&P Global said in its latest survey of purchasing managers, but the trend might be short-lived as price pressures and the war in Ukraine are weighing on the sector.

The final manufacturing PMI for the euro zone's second-biggest economy in April rose to 55.7 points from a 19-month low at 54.7 in March. It beat a 55.4 flash estimate, but was still below the index's historic average.

Growth in April was carried by improved new orders, according to the survey, as clients made advanced purchases in anticipation of even stronger price hikes and further supply problems going forward.

"This is worrying evidence that suggests inflation expectations have become de-anchored", S&P Global economist Joe Hayes said in a statement.

He said the positive April trend, which included all sub-indices except for delivery times, could be "short-lived" and demand conditions could worsen soon as clients advancing their orders now could hesitate ordering at higher prices in the future.

Output volumes rose slower than new business, S&P Global said, adding that French manufacturers kept hiring new staff in April.

However, continued supply problems and delivery delays - blamed on the Ukraine war and the COVID-19 situation in China by surveyed purchasing managers - weighed on production, S&P Global said.

(Reporting by Tassilo Hummel; Editing by Toby Chopra)