Brian Acton, co-founder of WhatsApp (L) and Jan Koum, co-founder and CEO of WhatsApp
Brian Acton, co-founder of WhatsApp (L) and Jan Koum, co-founder and CEO of WhatsApp speak at the WSJD Live conference in Laguna Beach, California October 25, 2016.REUTERS/Mike Blake

(Reuters) - Brian Acton, co-founder of WhatsApp, now owned by Facebook Inc, will leave the messaging service company to start a new foundation, he said in a Facebook post on Tuesday.

Acton spent eight years with WhatsApp, which Facebook bought in 2014 for $19 billion in cash and stock.

A Stanford alumnus, Acton co-founded WhatsApp with Ukrainian immigrant Jan Koum in 2009. The duo worked at Yahoo before starting WhatsApp.