ZURICH, Aug 29 (Reuters) - Syngenta AG may seek partners to help improve its product lineup after a thorough review in the wake of a rebuffed takeover approach from Monsanto Co, the agrichemicals group's chairman told a Swiss newspaper. Syngenta's board is under pressure from shareholders to show how it plans to generate value after turning its back on Monsanto's $47 billion cash-and-share offer, which it said undervalued the company and had too great an execution risk. In an interview with Finanz und Wirtschaft, Michel Demare said it was too early to discuss what steps Syngenta planned to boost its results. But he added: "We will subject our product portfolio to a total review, especially on the seed side. Then we will see if there are appropriate transactions to improve... More