"Time is critical. New services don't just spring fully formed from out of the ground and we're now losing time.
The Corporation had hoped to get the go-ahead for BBC Three, BBC Four, two children's services and five radio networks in time for an autumn launch.
"This is extremely frustrating for us," said the outgoing chairman of the BBC's board of governors, Sir Christopher Bland.
"At this stage, I find it hard to believe that there can be any additional information still to be provided."
Sir Christopher said he was worried that the delay might jeopardise the BBC's position in the digital market.
"Time is critical. New services don't just spring fully formed from out of the ground and we're now losing time.
"It is, of course, one of the frustrations of public service broadcasting that we have to ask permission to launch new services. It's right that we do, but we ought to have a timely response."
A BBC spokeswoman said: "The chairman was expressing his understandable disappointment at the delay, especially given that he is leaving the BBC at the end of September."
The Department for Culture, Media and Sport (DCMS) had hoped to reach its decision by the end of spring, but is now reluctant to set a new deadline.
"The proposals for the new services are likely to make a large impact on TV not just in the BBC but also in the commercial sector," a spokesperson told BBC News Online.
"The department wants to take time to consider the proposals and make sure it makes the right decision."
The decision on whether to let the services go ahead lies in the hands of new Culture Minister Tessa Jowell.
But the delay has nothing to do with Ms Jowell's promotion to the post after the election, at the expense of Chris Smith, the spokesperson said.
"The department felt that it needed further clarification of some of the points [the BBC] put in their proposals, so even if we had not had a new team it would have been the same situation."
Renamed
BBC Three and BBC Four would be relaunched versions of current digital channels BBC Choice and BBC Knowledge.
BBC Knowledge would be renamed BBC Four and be aimed at the same kind of audience as Radio 4.
BBC Choice, home to programmes like the entertainment news show Liquid News, would be renamed BBC Three and aimed at younger viewers - who have been deserting the BBC.
BBC Three would provide competition for BSkyB's Sky 1 and MTV, while its plans for a new children's channel could pose a threat to Nickelodeon and the Cartoon Network.