BRUSSELS (Reuters) - The European Commission said on Monday that it took note of the referendum on migrant quotas in Hungary on Sunday and that it was up to Budapest to deal with the outcome.

Almost all Hungarians who voted in Sunday's referendum rejected the European Union's migrant quotas but turnout was too low to make the poll valid, frustrating Prime Minister Viktor Orban's hopes of a clear victory with which to challenge Brussels.

"If the referendum had been legally valid, our comment would have been that we take not of it. Since it was declared legally void by the Hungarian electoral commission we can now say that we also take note of it," Commission spokesman Margaritis Schinas told a regular news briefing.

"We believe it is for the Hungarian government to decide how to deal with the outcome of this national referendum," he said.

(Reporting by Jan Strupczewski and Philip Blenkinsop)