The band were known to be reuniting for a tour in 2013 to mark their ten-year anniversary, but it was previously unclear if they planned to release new material.
"Me and the girls are chatting about ideas right now. It's not definitely just a one-off single. That's what we are talking about at the minute," Walsh told the Daily Star Sunday.
"We will have to see what happens but I'm certainly not ruling out a studio album just yet. It will be the Girls Aloud sound but moving forward with a twist."
She added: "I'm really, really excited about the Sugababes reforming. It will be really good if we are both releasing at the same time because that's how we started. We had a healthy rivalry and it will make us both raise our games."
Sources have also now suggested that the reason behind the Girls Aloud comeback being delayed until 2013 was to allow enough time to record an album.
> Girls Aloud 'issued Sarah Harding rehab ultimatum for reunion'
Watch Girls Aloud perform 'The Promise' live at The Brit Awards 2009 below: