Barring any last-minute change of plans, she is expected to move sideways away from youth programmes to work for David Liddiment, the BBC's new head of entertainment, co-ordinating independent productions in London.
A spokeswoman for Ms Street-Porter, one of broadcasting's most colourful and high profile executives, said she could neither confirm nor deny the report, and Ms Street-Porter would not comment.
BBC Television said it could not confirm the changes. But well-placed sources within the corporation said the move was both expected and imminent.
Ms Street-Porter, 48, was responsible for setting up Def II, the block of early evening BBC 2 youth programmes, including Reportage, The Rough Guides to travel and careers and Dance Energy, presented by her boyfriend, Normski. It followed her success in devising Network 7, for Channel 4, the 1980s prototype of a subsequent genre of informational programmes.
But Def II has had a mixed reception and its programmes were criticised on last Sunday's edition of Biteback for attracting only 14 per cent of the 16 to 24 age group they are aimed at: 14 per cent of pensioners also watched. This compares with 23 per cent of 16- to 24-year-olds watching Channel 4 youth programmes, such as The Word.
Ms Street-Porter's supporters within the BBC, who include John Birt, the director-general, say that she is both talented, fun and 'an enabler' who gets things done. This autumn she won a Prix Italia for her production of The Vampyr. The BBC's range of youth programmes also means it broadcasts some hard-edged factual programmes with minority appeal.
But others say the Manchester-based department she heads, which produces Ruby Wax, has had a poor track record in introducing new hit entertainment shows at a point when the BBC is desperate to reassert its ability to entertain: they point to flops such as Style Trial and Bobby Davro - Public Enemy Number 1. Manchester has also been an unlikely setting for her.
She has also seen her ambitions to rise to the top within the BBC thwarted. The controllership of BBC 2 went to Michael Jackson, while Matthew Bannister became controller of Radio 1.
The Radio Authority announced yesterday that Devonair, the commercial radio station based in Exeter since 1980, had lost its licence and that the two frequencies would be taken over from 1 January 1995 by Gemini Radio.