Dreamworks Animation filed Wednesday with regulators for an initial public offering of stock. The company is part of the Dreamworks studio formed in 1994 by Hollywood moguls David Geffen, Jeffrey Katzenberg and Steven Spielberg. Goldman Sachs and J.P. Morgan are serving as joint book-running managers of the offering. The announcement comes amid a simmering dispute between two cartoon-movie rivals, media giant Disney ( DIS) and red-hot animation studio Pixar ( PIXR). Pixar has said it intends to wind down the companies' collaboration at the end of their current agreement.