Swiss food giant Nestle plans to use its global marketing power to sell Starbucks products outside of the US chain's coffee shops, under a $US7.15 billion ($A9.48 billion) deal that both sides have announced.

Starbucks agreed to sell Nestle the perpetual right to market its coffee and foods products, a business that has been generating annual sales of $US2 billion.

As part of the deal, which is to be closed by the end of the year, some 500 Starbucks employees in Seattle will become Nestle staff.

"This global coffee alliance will bring the Starbucks experience to the homes of millions more around the world through the reach and reputation of Nestle," Starbucks chief executive Kevin Johnson said.

For Nestle, which already owns the Nescafe and Nespresso brands, the agreement is part of its strategy to focus on promising business segments.

"This transaction is a significant step for our coffee business, Nestle's largest high-growth category," Nestle chief executive Mark Schneider said.