One of the key executives who has been involved in building Facebook into the worldwide phenomenon it now is is leaving the company.

According to reports stateside, Ben Ling, who also previously worked at Google, is leaving to pursue "other interests", although is being very secretive as to what these may be.

Ling holds the official title of director of platform product marketing at the web company.

He is the fourth key executive to leave Facebook since February, following the departure of chief revenue officer Owen Van Natta, vice-president of product management Matt Cohler and chief technology officer Adam D'Angelo.

The company is also mooted to be still searching for a new vice-president of engineering and a vice-president of product.

And its platform product marketing team is currently being reviewed by Elliot Schrage, who was recruited from Google's public policy unit to lead Facebook's communications and public policy.