Dean Valentine's days of being president of UPN are officially over. The change comes one month after UPN and CBS' parent company, Viacom Inc., announced plans to merge operations between the two networks.

Viacom gave no explanation for Valentine's departure, which was announced late Friday. However, Valentine's departure was expected by many in the industry, especially since it was clear that the restructuring placed UPN under the control of CBS.

Last month, at the time Viacom released its plans, Kerry McCluggage, who helped launch UPN, resigned as head of the Paramount Television Group, which had overseen UPN before it was put until control of CBS.

It's likely that Valentine also saw the writing on the wall. In September, Valentine filed a breach-of-contract suit against his own company claiming he was owed more than $22 million in bonuses. The suit is still pending.

Valentine was named UPN's president in 1997, two years after the launch of the network. While it is still struggling, UPN has made large strides in both audience numbers and reach.