Warner Chilcott Plc said privately held Leo Pharma would re-acquire the U.S. rights to its topical psoriasis treatments for about $1 billion, sending the specialty pharmaceutical company's shares up 4 percent.

The deal will result in a one-time gain of about $450 million, or about $1.79 a share, for Warner Chilcott.

Leo Pharma is re-acquiring exclusive product licensing rights of Taclonex, Taclonex Scalp, Dovonex and all products in Leo's development pipeline, including the inventories of the products.

Net cash proceeds, which are expected to be about $980 million, will be used to repay and terminate its existing senior secured credit facilities and partly to finance the pending acquisition of Procter & Gamble Co's pharmaceuticals business, Warner Chilcott said in a statement.

Warner Chilcott shares rose 4 percent to $20.65 in premarket trade. They closed at $19.77 Tuesday on Nasdaq. (Reporting by Anuradha Ramanathan in Bangalore; Editing by Aradhana Aravindan)