The satellite TV firm said it wanted to ramp up its PR acitivites in the coming months and needed an agency with a strong regional presence.
Dubai-based IPN will take over the retained account from 8 May. Vida Rizq, PR and customer marketing manager at Showtime, said: "We were looking for a regional agency that was creative and able to think outside of the box.
"There really isn't a single agency that is strong everywhere in the region. We were looking for support in our key markets of Egypt, Kuwait, Saudi Arabia and the UAE. We have had enormous success in the past year with the level of coverage that we have been getting, but now its time to turn it up a notch."
Showtime will continue to use financial PR agency Citigate to help manage its corporate communications.
The company has also announced that it is launching a new sports channel and rebranding its exisiting Showtime Sport channel. From 1 May Showtime Sports becomes Sportsnet World.
The channel will feature Coca-Cola Championship Football, Guinness Premiership Rugby, Premier League Darts and European PGA Tour Golf. It will also show the Rugby World Cup in 2007 and 2011, and The Ryder Cup golf.
Sportsnet America will focus on North American Sport, with an emphasis on live sport and next day replays. Sports that will be shown include football, hockey, Nascar, basketball and wrestling.
Peter Einstein, president and CEO at Showtime Arabia, said: "Adding Sportsnet World and Sportsnet America to our top bouquet will add value to our subscribers whatever their sporting interests. Watching sports is more than entertainment – it's a way of life and nobody knows how to celebrate victories better."