Nearly 10 percent of some 2,000 species of European wild bees are threatened with extinction, according to a study published Thursday.

The study released by the European Commission, the EU executive arm, is the first on the European wild bee population, less known than the domestic variety but just as important to pollination of crops.

"The report reveals that 9.2 percent of European wild bee species are threatened with extinction, while 5.2 percent are considered likely to be threatened in the near future," the commission said.

The assessment was published as part of the International Union for Conservation of Nature (IUCN) European Red List of Bees and the Status and Trends of European Pollinators (STEP) project.

Its authors said the study provided the "best understanding" so far on the 1,965 species surveyed but added that knowledge was incomplete because of an "alarming lack of expertise and resources."

The IUCN said the study, which was co-funded by the European Commission, demonstrates the urgency in investing in research to halt the decline of wild bees which, it added, play "an essential role in pollinating crops."

"If we don't address the reasons behind this decline in wild bees, and act urgently to stop it, we could pay a very heavy price indeed," said Karmenu Vellu, the European Commissioner for the environment.

The commission said 84 percent of the main crops grown for human consumption in Europe require insect pollination to enhance product quality and yields.

Bees are threatened by the "large-scale loss and degradation" of their habitants resulting mainly from intensive agriculture and the use of insecticides and fertilisers.

"Climate change is another important driver of extinction risk for most species of bees, and particularly bumblebees," the commission said.