Nokia is working with Goldman Sachs to arrange the sale of its luxury phone subsidiary Vertu. It remains unclear exactly how much Vertu is worth, Reuters said Thursday, but the company typically earns Nokia an estimated $268-$402 million in annual revenue. Vertu is best known for its expensive handsets that feature luxuries such as sapphire crystal keys, gold accents and prices that reach several thousands of dollars and beyond. Private equity groups are already interested in the brand Reuters said, citing a Financial Times report that claimed luxury brands will likely also have interest in purchasing Vertu. Vertu has more than 90 retail locations around the globe.