German drug and crop chemical maker Bayer clinched a $66 billion takeover of U.S. seeds company Monsanto on Wednesday, ending months of wrangling with a third sweetened offer that marks the largest all-cash deal on record.Bayer and Monsanto have signed a definitive merger agreement under which Bayer will acquire Monsanto in an all-cash transaction valued around $66 billion.

The deal will create a company commanding more than a quarter of the combined world market for seeds and pesticides in a fast-consolidating farm supplies industry.

The $128 a share deal, up from Bayer’s previous offer of $127.50 a share, is the biggest of the year so far and the largest cash bid on record.