Monte dei Paschi contacts banks to back 5 bln euro cash call - source

LONDON/MILAN, July 27 (Reuters) - Banca Monte dei Paschi di Siena has asked at least eight banks to guarantee a five billion euro ($5.49 billion) cash call as Italy's third-largest bank races against the clock to comply with regulators' demands to strengthen its balance sheet, a source familiar with the matter told Reuters.