ROME (Reuters) - Banca Monte dei Paschi di Siena's (>> Banca Monte dei Paschi di Siena SpA) top management met Italy's economy minister and representatives from investment banks JPMorgan and Mediobanca in Rome on Friday, a Treasury source said.

The struggling bank asked the European Central Bank for an extension to a capital-raising plan, but a source told Reuters on Friday that the central bank rejected the request.

That increases pressure on the government to intervene to save Monte Paschi, Italy's third-biggest bank, from being wound down. JPMorgan and Mediobanca must decide whether to back the cash call.

(Reporting by Giuseppe Fonte, writing by Isla Binnie, editing by Steve Scherer)