April 20 (Reuters) - Telefonica SA:
* TELEFONICA - FILES FOR POTENTIAL MIXED SHELF OFFERING; SIZE NOT DISCLOSED- SEC FILING
* TELEFONICA SAYS MAY OFFER ORDINARY SHARES, INCLUDING IN FORM OF ADSS, OR RIGHTS TO SUBSCRIBE FOR ORDINARY SHARES OF CO, IN ONE OR MORE OFFERINGS
* TELEFONICA SAYS TELEFÓNICA EMISIONES, S.A.U. MAY OFFER IN ONE OR MORE SERIES DEBT SECURITIES,WHICH ARE FULLY AND UNCONDITIONALLY GUARANTEED BY CO Source text: (bit.ly/2HLSTGQ) Further company coverage: