"MILAN, Jan 8 (Reuters) - Italy's Banco BPM has filed a complaint with the national antitrust authority over UniCredit's for the bank, a source close to the matter said on Wednesday. Banco BPM had previously complained to that UniCredit's 10 billion euro ($10.32 billion) all-share bid could be seen merely as a way to block its buyout proposal for fund manager Anima. In its complaint with the competition watchdog, Italy's third-largest bank alleged that UniCredit’s exchange offer was aimed at eliminating a troublesome competitor and stifling its operations, the source said. Banco BPM and the Italian antitrust authority declined to comment. News of the Banco BPM's antitrust complaint was first reported by Il Messaggero daily on Wednesday. ($1 = 0.9691 euros)".