* Big Japan banks' report July-September results

* When: Mizuho and SMFG on Nov 13, MUFG on Nov 18

* What: Profit down 15 pct at MUFG, SMFG; Mizuho back to black

By David Dolan

TOKYO, Nov 12 (Reuters) - Mitsubishi UFJ Financial Group (8306.T: Quote, Profile, Research) and Sumitomo Mitsui Financial Group (8316.T: Quote, Profile, Research), two of Japan's biggest banks, are likely to report 15 percent profit declines for the July-September quarter, as weakness in the world's second-largest economy continues to sap lending.

Bucking the trend will be rival Mizuho Financial Group (8411.T: Quote, Profile, Research), the country's second-largest bank by assets, which is expected to book its first profit in five quarters, aided by lower bad loan costs and an improvement in its massive equity portfolio.

The likelihood of further capital raising will continue to be a concern. Japanese banks have already raised $15 billion this year through issuing common equity, according to Thomson Reuters data, and analysts believe more will be needed to eventually meet stricter global requirements. [ID:nT306019]

Analysts are also concerned about the potential collapse of struggling carrier Japan Airlines Corp (9205.T: Quote, Profile, Research), which could cause a spike in bad-loan costs.

Mitsubishi UFJ, Mizuho and Sumitomo Mitsui Financial Group (8316.T: Quote, Profile, Research) -- known as Japan's "megabanks" -- continue to be hurt by the weak economy at home, where they do the bulk of their business.