• by Joe Mandese  @mp_joemandese, August 15, 2011

Interpublic may initially have acquired a stake in Facebook for strategic reasons, but it's realizing a considerable profit, according to a transaction disclosed Monday morning in a filing to the Securities and Exchange Commission.

The parent of Initiative, Universal McCann, Reprise Media and other media and full-service agencies, Interpublic said it has agreed to sell about half its stake in the social network in a "privately negotiated" transaction that will net it $133 million in cash.

The company did not disclose the buyer of the stake, but said it would record a $132 million pre-tax gain on the transaction and would use the proceeds to help fund a repurchase of between $300 million and $450 million shares of Interpublic stock.

Already, it has acquired 16.8 million shares of Interpublic stock, for about $187.5 million in cash, including fees, and the repurchase program has no expiration date.

Interpublic did not disclose what its remaining stake in Facebook will be, but Chairman-CEO Michael Roth stated: "When an attractive opportunity to divest a portion of our position recently presented itself, we decided that it made sense to do so."