Most of the bidders seeking to buy a portion of Starbucks' China operations have submitted offers valuing the business at as much as $5 billion, said two people who have knowledge of the deal discussions. That quotation would make a potential deal one of the most valuable China unit divestments by a global consumer company in recent years. The offers, which have not been reported previously, would let Starbucks push ahead with the sale in a market where it faces sluggish economic growth and stiff competition from local brands.