BERLIN (Reuters) - All 27 countries in the European Union will support giving the European Central Bank a bigger supervisory role for the bloc's banking system at next week's summit, German newspaper Die Welt reported on Friday, citing EU diplomats.

European Council President Herman Van Rompuy has mustered the support of all member states to ask the European Commission to draw up concrete plans for making the Frankfurt-based ECB the new central oversight body as soon as possible, it said.

"Van Rompuy has the backing of all 27," the newspaper quoted one diplomat as saying.

The paper said there had been no decision yet on what would happen to the London-based European Banking Authority (EBA), the existing supervisory body whose role has been criticized, among others by German Chancellor Angela Merkel.

(Reporting by Stephen Brown)