Aldo Liguori, corporate vice-president and head of global comms and PR, is to step down at the end of October after seven years with the mobile phone giant.
Ligouri moved to London to take up his role at Sony Ericsson in 2004. Before that, he headed comms for Sony Europe in Berlin for four years.
He is not understood to have a specific job to go to but is expected to take a global consumer comms role outside of the telecoms sector.
Sony Ericsson is expected to name Liguori's successor in the coming weeks.