By Foo Yun Chee BRUSSELS (Reuters) – Ukraine’s national regulatory authority NCEC is set to sign up to the European body of telecoms regulators this month following a push by EU industry chief Thierry Breton, a move that could help millions of Ukrainian refugees to stay connected with low roaming tariffs. In April, Deutsche Telekom and a group of other top European telecom companies agreed to cut wholesale roaming charges levied on Ukrainian peers for three months to help Ukrainian refugees stay in touch with families back home. NCEC has put in a request to the European Commission to join the …