While Japanese brewers will diversify into other beverage products to cope with the new dynamics of the domestic market, numerous obstacles to becoming comprehensive drink providers could undermine this reorientation and hurt credit quality, Moody's Investors Service Inc. said Tuesday in a special report.

"We believe that the shift to being comprehensive drink providers will give the beer companies business opportunities in the broader categories and therefore increase sales, considering the only limited growth expected in the domestic beer market," said Moody's analyst Chieko Matsuda, author of the report.

"Profitability, however, will decrease over the intermediate term, unless companies can cope with numerous factors."