(Sharecast News) - Drinks giant Diageo has backed its guidance to deliver organic net sales growth towards the upper end of its mid-single digit range on Wednesday.Chief executive Ivan Menzes also reaffirmed the company's targeted 175 basis points operating margin improvement over the three years ending 30 June 2019.In a speech at an investor conference in New York later in the day, Menzes will say: "Diageo has delivered strong performance over the past two years with consistent mid-single digit organic top line growth; upweighted investment in our brands; as well as organic operating margin expansion and strong cash flows."During the same period we have generated attractive total shareholder returns and, from fiscal 17 to fiscal 19 H1, have returned £7bn to shareholders via dividends and share buy-backs."The CEO also said in the statement that looking ahead to the end of fiscal 2022, he expects Diageo to maintain organic net sales growth in the mid-single digit range and to grow organic operating profit ahead of net sales in the range of 5% to 7%.At 1255 BST, the shares were down 1.2% at 3,286.00p.