MEXICO CITY/SAO PAULO, Jan 2 (Reuters) - Brazil and Mexico are working together to develop a regional plan to keep trade in poultry and eggs flowing between the two countries despite potential avian flu outbreaks, Mexico's agriculture ministry said on Tuesday.

The plan seeks to map out areas of either country unaffected by a potential outbreak to keep trade from those regions moving, the ministry said in a statement, citing health safety agency head Javier Calderon.

Brazil, the world's No. 1 poultry exporter, has seen recent cases of highly pathogenic bird flu in wild and backyard poultry. Mexico, which exports just a fraction of the poultry it produces, reported its first commercial case of the season in November.

Setting up a "containment zone" under World Organization for Animal Health (WOAH) guidelines could avoid an otherwise-nationwide ban on exports if avian flu hits commercial flocks.

Brazil is also looking to start imports of Mexican avocados "soon," according to Brazilian agriculture official Roberto Perosa.

Mexico is the world's top avocado supplier, though almost all of them are bound for the U.S. (Reporting by Kylie Madry in Mexico City and Peter Frontini in Sao Paulo; Editing by Bill Berkrot)