Monsanto has abandoned plans to acquire Syngenta, a merger which would have created an agricultural giant, after the Swiss seeds company rejected its latest bid of Swiss Francs 470 per share.

In a statement, Monsanto said while it continued to believe a combination with Syngenta would have created tremendous value for shareowners of both companies and farmers, the enhanced proposal did not meet Syngenta’s financial expectations.

“Without a basis for constructive engagement from Syngenta, Monsanto will continue to focus on its growth opportunities built on its existing core business to deliver the next wave of transformational solutions for agriculture,” Monsanto said.

Syngenta confirmed it had rejected the sweetened offer because it significantly undervalued the company and was fraught with execution risk. The company added that Monsanto did not provide sufficient detail on certain key issues which would have allowed Syngenta to properly asses the new entity, which would have been 30% owned by Syngenta shareholders.

The issues which Syngenta said lacked clarity were: an estimate of total cost and revenue synergies; assumptions regarding net sales proceeds of seeds and traits; the nature and extent of regulatory covenants that Monsanto was prepared to offer; the assessment of risks and benefits from a tax inversion to the UK.

Michel Demaré, chairman of Syngenta, said: “We engaged with Monsanto in good faith and highlighted those key issues which required more concrete information in order to continue a dialogue. Our board is confident that Syngenta’s long-term prospects remain very attractive with a leading portfolio and a promising pipeline of new products and technologies. We are committed to accelerate shareholder value creation.”

Monsanto said it will now focus on more than doubling fiscal 2014 earnings by 2019 and will resume its share repurchase program “as soon as practical”.