A member of the company's executive committee, Malcolm was appointed to head the company's sales and marketing in September 2000.
His responsibilities are being split between Ron Anderson, who has been appointed to the executive committee in the new role of chief customer officer, and Andy Fennell, formerly marketing and innovation director for Europe, who will become chief marketing officer, reporting to chief executive Paul Walsh.
Walsh said: 'Under Rob Malcolm, Diageo has established itself as a leading marketer in the world of consumer goods. I thank Rob for the significant contribution he has made to the success of Diageo's brands globally. To build on that success, I want to sharpen our focus on the critical role of sales with the appointment of Ron Anderson to the new role of chief customer officer.'
Diageo's brands include Johnnie Walker, Guinness, Smirnoff, J&B, Baileys, Cuervo, Tanqueray, Captain Morgan, Crown Royal, Beaulieu Vineyard and Sterling Vineyards wines.