Splenda is being touted as the only no-calorie sweetener made from sugar and is already available in the US, Canada and Australia. It has been chemically altered to pass through the body without being digested.
Splenda contains no tooth-rotting or fattening agents and can be used like sugar.
It is being produced by Tate & Lyle and distributed through McNeil and is expected to be available in the shops by the end of the year.
MCBD seized the Benecol brief from Saatchi & Saatchi in August after a competitive pitch and dropped the brand spokeswoman, Carol Vorderman.
The review is thought to have been prompted by client dissatisfaction with Saatchis' creative work.
Initiative Media, the media agency of record for Benecol, is expected to handle media buying for Splenda.