Sony (www.sony.com) and Time Warner (www.timewarner.com) have announced that they would merge their Columbia House (www.columbiahouse.com) joint venture with online music retailer CDnow (www.cdnow.com). The new, as yet unnamed company will have an initial online customer base of about 4.3 million consumers ñ with 2 million from Columbia House and 2.3 million from CDnow. The aim of the merger is to build a ""major entertainment, e-commerce and direct marketing company,"" and to have it serve as a cross-promotional platform.""With the commercial arrival of the digital downloading of music, it also gives us an important platform for offering consumers the opportunity to order or download music instantly,"" said Gerald M. Levin, Chief Executive at Time Warner.