Thompson started work on July 14 and will assess and acquire properties in all the company's territories including the UK, Canada, Holland, Belgium and the US home entertainment market.
She will remain in Los Angeles and report to E1 president Patrice Theroux. Thompson joined SPWAG in January 2007 and during her tenure secured multi-territory deals on titles like Hachiko starring Richard Gere and Crank 2 with Jason Statham.
She also signed this summer's releases Iron Man and The Incredible Hulk for select territories and was instrumental in bringing Peter Jackson's District 9 to Sony.
Prior to SPWAG, Thompson was responsible for acquisitions across Europe for UK-based distributor Momentum Pictures and worked at Working Title on films such as Elizabeth, Notting Hill and Bridget Jones's Diary.
'I'm thrilled to have been given this chance to work with Patrice and the E1 team in building this exciting and dynamic company,' she said.
'While I had an incredible experience at Sony, the opportunity to join E1 as they become a new international force in film and distribution was impossible for me to turn down.'