Major leadership changes were announced this week at the Colombian telecommunications regulator (CRC) and the Spanish telecom operator Telefónica.

CRC’s executive director, Carlos Andrés Rebellón, has resigned his position. He had been the head of the CRC since November 5, 2010. In his resignation letter, Rebellón cited personal reasons, thanked Colombia’s president, Juan Manuel Santos Calderón, and ICT minister, Diego Molano Vega. His last day will be October 8, 2012. The name of his replacement had not been released yet.

The Spanish group Telefónica also announced changes in its governance. Citing personal reasons, chief operating officer of Telefónica S.A., Julio Linares, has decided to step down from his executive position and leave the company where he has worked for more than forty years.

His resignation led the company’s executive chairman, César Alierta, to propose a number of changes in senior-level management to the board.

Telefónica’s board of directors decided to appoint José María Álvarez-Pallete as the new COO. Previously, he was in charge of operations in Europe.  Replacing him, Eva Castillo, a member of the board of directors, was appointed chairwoman and CEO of Telefónica Europe; she will remain on the board of Telefónica S.A.

Also, Santiago Fernández Valbuena, chairman and CEO of Telefónica Latinoamérica, will join the board of Telefónica S.A., while maintaining his current executive responsibilities.  He is replacing David Arculus, who is leaving for personal reasons.