As even digital music revenue growth falters because of rampant file-sharing by consumers, the major record labels are moving closer to releasing music on the Internet with no copying restrictions -- a step they once vowed never to take. Executives of several technology companies meeting here at Midem, the annual global trade fair for the music industry, said over the weekend that at least one of the four major record companies could move toward the sale of unrestricted digital files in the MP3 format within months.