The deal is being billed as a merger of equals, where Dow and DuPont shareholders will receive equal stakes in the combined company.

The firms are two of the largest chemical companies in America and the deal is expected to reshape the chemical and agricultural industries. The combined company would have about $90bn in total revenue, with debts of $18bn. The deal will see the new entity look for synergies and cut costs to the tune of $3bn.

The two companies had a combined agri-chemical turnover of $13bn for the first nine months of this year. The merger would see the combined companies now controlling about 40% of the maize corn, soya seed and related genetics market in the US, and 17% of the global crop protection market.

The new company will be called DowDuPont. It will then be split up into three businesses over the next two years which will be publicly traded - one in seeds and crop protection, one in materials (such as plastics) and one in speciality products and chemicals.

The deal means that there are as few as six global companies that sell crop seeds and pesticides. This deal could increase the pressure for remaining companies to merge, resulting in even less competition.