Amazon.com Inc said on Monday it had named Starbucks Corp chief operating officer Rosalind Brewer as director, making her the second black woman to serve on the e-commerce giant's board.

Brewer's appointment comes after Amazon last year said it was adopting a new policy to promote diversity on its board.

Amazon's ten-member board now has four women including Brewer, Jamie Gorelick, Judith McGrath, Patricia Stonesifer.

Brewer, who has been with Starbucks for nearly two years, was previously CEO of Walmart Inc's warehouse chain Sam's Club.

Brewer has also been appointed to Amazon's leadership development and compensation committee of the board, the company said in a regulatory filing.