Womenswear retailer Karen Millen will “take very seriously” any attempt by its founder, designer Karen Millen, to trade using its name.

Millen, who sold her interests in the business in 2004, revealed that she wants to trade under her own name again early this week. She plans to set up shop under either Karen or KM as the retailer Karen Millen owns the rights to the brand name.

The retailer has warned of trademark infringement if Millen goes agead as planned.

It said: “When Karen Millen and Kevin Stanford decided to sell the Karen Millen business for £120m in 2004 in order to pursue other interests, they sold all rights to the use of the Karen Millen brand name or any iterations of it. 

“Since the acquisition, the Karen Millen brand has gone on to become one of British fashion’s greatest successes, operating in 45 countries around the world and employing 1,700 people, including 1,100 in the UK and Republic of Ireland.

“Naturally, we take very seriously attempts by any third parties to trade on our name, goodwill and reputation, which would be in clear breach of our intellectual property rights.  We will always take measures to protect our brand, our company and our employees, as any business would.”

The retailer added that while it would be “delighted” to see someone with Millen’s talent back in the market, they believe that she would want any new venture to be successful in its own right and not to be confused with the Karen Millen brand which she sold in 2004.

Both founder Millen and her former husband, All Saints co-founder Kevin Stanford, are pursuing legal action against collapsed Icelandic bank Kaupthing for the way in which they lost a near 7% interest in Mosaic Fashions (now known as Aurora Fashions) the businesses’ former owner.