BERLIN (Reuters) - German Economy Minister Sigmar Gabriel has called for the number of EU Commissioners to be cut and for Brussels to reconsider how it allocates its budget, just over a week after Britons voted to leave the bloc.

"A Europe in which 27 Commissioners want to prove themselves doesn't make sense," he told the newspaper Neue Osnabruecker Zeitung in an interview published on Saturday. "It would be good to downsize in this respect."

British voters' decision in a June 23 referendum to quit the European Union has rocked global financial markets, thrown British politics into turmoil and raised concerns about the EU's future prospects.

Gabriel said the EU must check whether it should still put around 40 percent of funds towards agriculture while much less money is pumped into research, innovation or education. He also said the EU should build up a joint European army.

Gabriel, who is also vice chancellor, said a Brexit did not endanger the EU and even raised the possibility of Britain re-joining the EU in a few decades, especially given that young people voted overwhelmingly to remain in the EU.

A Brexit was not irreversible, he said at a European conference of his Social Democratic (SPD) party in Berlin on Saturday. "I'm sure that historically this is an episode rather than an epoch," he said.

Gabriel urged the EU to be resolute in dealing with Britain to prevent "copycats" from adding to the bloc's troubles.

He said the EU should invest more and do more to tackle unemployment. He criticized the EU for not planning to involve national parliaments in the ratification of CETA, a free trade deal between the EU and Canada: "You can't be more foolish than that - that destroys trust in European democracy."

In a video podcast released on Saturday, Chancellor Angela Merkel said leaders of the 27 states that will be left after Brexit had identified areas where the bloc needed to become more effective such as competitiveness, jobs, growth, internal and external security, combating terrorism, protecting its external borders and improving what it offers young people.

She gave no other details.

In the newspaper interview, Gabriel accused Brussels of "petty" involvement in issues that could be better handled by municipalities or states.

He said Britain should be fairly treated but added: "It would not be acceptable for the British government to now consult on quitting and on its future relations with the EU at the same time so it can ultimately pick the best of both sets of negotiations."

Gabriel said the EU would certainly accept Scotland as a member in its own right if the country leaves the United Kingdom and wants to join the EU.

(Reporting by Michelle Martin and Andreas Rinke; Editing by Tom Heneghan)