Spanish broadcasting groups Antena 3 and La Sexta are negotiating a merger.The two private-sector TV operators plan to create a joint shareholding company, 80% owned by Antena 3, Spanish financial daily Expansion reported on Thursday. The partners would share management of the holding company. The independence of their core terrestrial channels and digital terrestrial services would be maintained. Antena 3 informed Madrid’s CNMV stock market regulator Thursday morning that no agreement had been reached with La Sexta. Antena 3/La Sexta negotiations come as Prisa, Spain’s biggest media group, is reportedly in talks to sell its broadcaster Cuatro and a 20% or more stake in satcaster Digital Plus to Mediaset-controlled Spanish network Telecinco.