Mutya and Keisha have joined forces with original member Siobhan Donaghy to form new group Mutya Keisha Siobhan.
And Heidi, who replaced Siobhan in 2001, said: "I think good luck to them. I saw the girls at V Festival a few weeks back and said hello and wished them all the luck. I've not heard any of the songs yet but I'm sure they'll be great.
"The three of them are brilliant singers, so I'm looking forward to hearing the songs."
Heidi insisted there was no rivalry between the two groups.
"There have been enough line-up changes and stuff that I think it doesn't make any difference now," she said.
Heidi is currently on a break from the Sugababes and has some potential TV and stage projects in the pipeline.
"We've not actually split, we kind of want to take time out and do our own thing," she explained.
"I've been in talks with a few different TV projects at the moment, in talks about some West End stuff. I'm kind of keeping my options open but it's nice and exciting to be looking at different things. It is nice not living out of a suitcase but I love being in Sugababes, it's such an amazing job and I'm so lucky that we've had 11 years so far. But it is nice to not be packing suitcases every two minutes and have a normal routine."
:: Heidi stars in Asda's Tickled Pink campaign for the Breast Cancer Campaign and Breast Cancer Care. Visit asda.com for more information.
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