She was appointed assistant managing director of the supermarket group in July 2001. Weller joined Sainsbury's in 1999 as marketing director from Abbey National, where she was retail marketing director for three years. She joins the board on January 1.
Previously, Weller had worked for Mars Confectionery for 13 years, having joined as a graduate trainee. She has worked in a wide range of roles in sales, personnel management and marketing.
Also promoted to the board is Stuart Mitchell, who has held four senior roles within Sainsbury's UK business -- in procurement, primary agriculture, non-foods and strategy. In addition, he has worked for Shaw's, Sainsbury's US supermarket business.
Group chief executive Sir Peter Davis said: "Stuart's wealth of retail and trading experience and Sara's range and depth of management skills and experience, gained through working in various businesses, bring real value to our board.
"Both have made significant contributions to our business in their senior roles and I'm delighted with their promotions to executive directors."
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