LOS ANGELES--Sony Corp. has launched a review for its consolidated, estimated $300 million European media planning and buying business, sources said. Contending are Omnicom's OMD; Bcom3's Starcom Motive; WPP's MindShare; and Publicis and Cordiant Communications' Zenith Media. All but MindShare are incumbents. Presentations are scheduled for the week of March 25. At stake are the aggregate billings for Sony Electronics, Sony Music Entertainment, Sony Pictures Entertainment and at least part of Sony Computer Entertainment, according to sources. The search follows a $600 million U.S. media consolidation review won by Interpublic Group of Cos.' Universal McCann, New York, earlier this year. (MindShare's WPP sibling Mediaedge:cia, formerly The Media Edge, was the incumbent on Sony Electronics' U.S. business.) All of the European contenders participated in the U.S. review as well.