Facebook haemorrhages top staff -

It seems that it is not just shareholders who are losing interest in the social networking site Facebook. The company's high-ranking managers are starting to see the writing on the wall, cleaning out their desks and moving on for pastures new.

Facebook has admitted that four high-ranking managers have left the company last week.

Ethan Beard, director of platform partnerships, Kate Mitic, platform marketing director, Jonathan Matus, mobile platform marketing manager and Ben Blumenfeld, design manager, have all decided that the grass will be greener somewhere else, TechDay reports.

The managers all have said publicly that while they enjoyed their time at Facebook, they are ready for new, more exciting challenges.

Beard, for example, said that he left Facebook "with mixed emotions" after almost five years. He did not say what he planned to do next.

Mitic said that after two "amazing" years at Facebook, she's moving on to work on a mobile startup company she's launching based in California. Matus seemed to say something similar.

Blumenfeld is moving on to the Designer Fund, an angel fund for designers he co-founded. The Designer Fund supports entrepreneurial designers whose businesses have a positive social impact.

But what is alarming for Facebook is that if the four exits are a larger trend, then Facebook might have to make some changes to retain high-ranking managers.