Facebook share fee set at $2,500

Two of the most sought after social networking companies, Facebook and Zynga, have moved to prevent employees selling their privately held shares by imposing huge fees on any transactions.

Both have been tipped to list on the public markets in the next few years, and investors have been licking their lips at the prospect. Currently both are private, but have offered stock to employees.

To prevent these shares ending up in outside hands, Facebook has imposed a fee of $2,500 for each sale. Zynga, which developed the gaming phenomenon FarmVille, set the charge at $6,000.

Many private companies charge a fee for transactions in their shares, to cover the administration and transfer fees. Experts said the companies may want to limit their number of shareholders as those with more than 500 face increased disclosures to the regulator.