Lockstone is currently MD of Edelman's EMEA financial practice and will start at Aviva Investors in January 2010, reporting to Erich Gerth, global business development director.
He will lead external and internal global communication activities of the business, with a remit including media relations and public affairs.
Lockstone has been an MD at Edelman since 2005 and previously worked at Merlin Corporate and Financial Communications where he was director of banking and financial services. He also has considerable in-house experience, having worked in senior communications roles with Alliance & Leicester, PwC and NatWest.
Gerth said: 'Paul's depth of experience across a broad spectrum of financial sectors and corporate communication activity will be invaluable to Aviva Investors as we continue to grow our global asset management footprint.'
Robert Phillips, CEO of Edelman UK, said: 'Paul has been a hugely valued member of the team at Edelman and a highly respected colleague. We are really sorry to see him go but obviously wish him the very best of luck for an exciting future in the City.'