By Ingrid Melander

BRUSSELS, Sept 25 (Reuters) - European Union interior ministers gave initial backing on Thursday to a fast-track scheme to attract highly skilled migrant workers from developing countries, hoping to compete with the U.S. Green Card system.

Ministers also rubber-stamped a “European pact on immigration and asylum” in which the bloc pledged to boost the fight against illegal migration while promoting legal migration and a common asylum policy.

The EU wants to be more competitive in a battle with other Western states for technology workers and hospital staff from the developing world, increasingly needed to plug labour gaps.

“There is agreement in principle about it,” German Interior Minister Wolfgang Schaeuble told reporters.

French Immigration Minister Brice Hortefeux said the only question was when the Blue Card system would begin. The Czech Republic wants existing curbs on the ability of workers from new EU states to work elsewhere in the bloc to be lifted first.

Spanish Labour and Immigration Minister Celestino Corbacho said he expected the scheme to be approved by year end.

The Blue Card will offer candidates speedier work permits, make it easier to find public housing, acquire long-term resident status and facilitate migrants’ families to join them.

Foreign highly skilled workers make up 1.72 percent of migrant workers in the EU, against 9.9 percent in Australia and 3.2 percent in the United States, EU figures show.

However analysts question whether the Blue Card scheme will work because it only offers access to one state at a time, so limiting the opportunities open to would-be migrants.

After 18 months working with a Blue Card in one EU state, an immigrant could work in another EU state but must apply for a new Blue Card there within a month of arrival.

The U.S. Green Card gives the holder the right to permanently live and work in the United States.

The EU asylum and migration pact endorsed on Thursday states that the bloc needs immigration but warns that it “does not have the resources to decently receive all the migrants hoping to find a better life here.”

With the pact, EU states agreed to cooperate better together and with migrants’ countries of origin to fight illegal immigration.

They agreed to expel more illegal migrants and not to carry out mass regularisations of illegal migrants but rather proceed on a case-by-case basis.

The pact will be endorsed by EU leaders at an Oct 15 summit. The European Commission estimates there are up to 8 million illegal migrants in the bloc. (Additional reporting by Ilona Wissenbach; Editing by Giles Elgood)