Facebook Director of Platform Partnerships Ethan Beard announced today that he is leaving the company after more than four years.

Beard publicly announced his departure with a Facebook post seen below. He did not reveal his next plans. Beard joined the Facebook team as director of business development in April 2008. Since January 2009 he has led worldwide developer relations and marketing for the platform, which has expanded significantly with the rise of social marketing and advertising platforms, as well as web and mobile integrations with Open Graph. Beard previously worked at Google as director of social media and director of new business development.

TechCrunch reports that Director of Media Partnerships Justin Osofsky has been promoted to director of platform partnerships and operations following Beard’s departure.

This is yet another top employee leaving the company since it went public in May. Director of Product Management Carl Sjogreen announced the end of his time at Facebook last week. Chief Technology Officer Bret Taylor announced his departure in June and Director of Corporate Communications Barry Schnitt recently left Facebook for Pinterest.

[Update 8/1/12 2:18 p.m. - Manager of Mobile Platform Product Marketing Jonathan Matus also announced today he's leaving Facebook "to explore new directions and entrepreneurial ideas." Matus joined the company in May 2011 after working for Google on Android product marketing.]

[Update 8/1/12 4:47 p.m. - Platform Marketing Director Katie Burke Mitic also announced that she will be moving on from Facebook after two years with the company. She hinted at creating a mobile start-up in a post on her Facebook Timeline.]