TOKYO, March 29 (Reuters) - Japanese automaker Mazda Motor and the energy unit of Panasonic Holdings said on Friday they have signed an automotive battery supply agreement.

Mazda and Panasonic Energy said in a joint statement they will disclose details of the partnership, which is for the supply of cylindrical automotive lithium-ion batteries, at an appropriate time.

(Reporting by Daniel Leussink; Editing by Kim Coghill)