The as-yet unnamed company would own the rights to Simon's hit shows including The X-Factor and Britain's Got Talent and then sell related merchandise in Philip's shops.
Kate met up with Philip – the owner of Topshop, the popular clothing company she designs a range for – and music mogul Simon at the end of June to work out a deal, it has been reported.
"Kate's been signed as a figurehead and style setter for the fashion end of the business," a source told the Daily Mail. "She will bring her expertise to the table, advising on all branding and style for clothes, hair and accessories.
"She will also be involved in finding and signing new bands and promoting them. Something that has also been talked about is Kate developing her own singing career and starting a music label."
Meanwhile, symbolic of the Croydon-born supermodel's pulling power, supermarket chain Asda have replicated the designer Balmain dress she made headlines wearing earlier this year. And within hours of the £16 limited edition replica hitting the rails on Monday, it had sold out.
"Women have been queuing this morning with sales very strong, some stores selling out within two hours of them being available," a spokesperson has confirmed.