BYD Co Ltd <002594.SZ><1211.HK>, a Chinese carmaker backed by billionaire investor Warren Buffett, said on Monday it had gained official permission to sell its electric buses in all European Union member states.

The "Whole Vehicle Type Approval" granted by EU - which came weeks after BYD announced its plan to build electric buses in Bulgaria with a local partner - marked its latest effort to tap green vehicle potentials overseas.

BYD has been promoting its electric vehicles in the Netherlands, Finland, Denmark, Canada, Uruguay and the United States among others.

Its Bulgarian plant, capable of building 40-60 vehicles each month, is expected to deliver its first sample electric bus in February, according to the official Xinhua news agency.

In October 2012, BYD secured an order of 50 electric cars from London cab service provider greentomatocars.

(Reporting by Fang Yan in BEIJING and Kazunori Takada in SHANGHAI; Editing by Ron Popeski)