LONDON — The launch of British Digital Broadcasting, the digital terrestrial net for the U.K., may be delayed by the European Commission.Following a formal complaint from Digital Television Network, the rival company backed by U.S. cable group NTL that lost out when BDB won its digital franchise last June, the EC is investigating the award through its Competition Directorate. BDB, a joint venture between the two biggest ITV network companies (Carlton Communications and Granada), has long-term programming supply deals with Rupert Murdoch’s satcaster BSkyB, which was originally part of the BDB consortium but was forced out by the ITC, the U.K.’s commercial TV regulatory org. The commission will investigate the BDB/BSkyB relationship and is believed to also be concerned about the prospect of the two main ITV companies virtually controlling digital terrestrial television in Britain. The ITC is unlikely to give BDB the final green light before the EC rules. BDB is planning to launch 20 out of a future total of 40 channels in the second half of 1998. Any delay will impact manufacturers getting digital equipment to consumers in time for Christmas next year.