Editor's note: Monsanto/Bayer report that the $128/share price would have an aggregate value of $66 billion - Bloomberg has reported it at $56 billion. We have corrected below.

Bayer AG has reached an agreement to acquire Monsanto Co. for about $66 billion to create the world’s biggest maker of seeds and pesticides, according to people familiar with the matter.

The German company agreed to pay about $128 a share and an announcement is planned imminently, said the people, who asked not to be identified because talks are private. Bayer’s supervisory board supports the deal, they said. Bayer is also offering an antitrust break fee of about $2 billion, one of the people said. If successful, it would lead to the biggest deal this year and the largest ever by a German company.

Bayer’s wooing of St. Louis-based Monsanto has played out against a backdrop of a rapidly consolidating crop and seed industry as falling prices weighed on profits. A series of big deals may leave just a few global players. China National Chemical Corp. agreed in February to acquire Syngenta AG, while DuPont Co. and Dow Chemical Co. plan to merge and then carve out a new crop-science unit.

Three Offers

Spokesmen for both companies declined to comment on the new proposal. Bayer rose 2.4 percent to 95.58 euros at 12:20 p.m. in Frankfurt trading. Monsanto gained 1.6 percent to $107.74 before the opening of U.S. markets.

Leverkusen, Germany-based Bayer first made an unsolicited offer for Monsanto of $122 a share in May, and then bumped that in July to $125. Both proposals were rejected by Monsanto as too low. Monsanto later granted access to some financial accounts to conduct due diligence. Last week, Bayer came back with a third offer of $127.50.

One impetus for Monsanto is the company’s ambition to become a one-stop shop for farmers, and to sell a comprehensive array of fertilizers and seeds to be used in conjunction with big data applications. That’s how farmers are going to increase productivity and yields to feed a growing world population, the company has said. For years, Monsanto pursued Swiss pesticide maker Syngenta to boost its farm chemicals portfolio, making three failed offers as recently as last year.

In the past two decades Monsanto has pioneered the commercialization of genetically modified organisms, or GMOs. GMO varieties of corn and soybeans now account for more than 90 percent of corn and soybean crops in the U.S.

Break Fee

That may account for the high break fee. The combination of both companies could account for more than 30 percent of the global crop-inputs business, stoking concern over whether the deal will be passed by competition authorities. The recent industry consolidation will also leave potentially fewer buyers for any assets sold off by Bayer-Monsanto to satisfy regulators.

Founded in 1901, Monsanto also used to produce pharmaceuticals and industrial chemicals, including highly toxic ones like polychlorinated biphenyls, now banned and commonly known as PCBs, and the herbicide Agent Orange, which was used by the U.S. military in Vietnam.Bayer was founded in 1863 and made its name by introducing heroin as a cough remedy in 1896 and then aspirin in 1899. Bayer’s stated ambition is to be the global leader in pharmaceuticals and chemicals for people, plants and animals.

To contact the reporters on this story: Aaron Kirchfeld in London at [email protected]; Dinesh Nair in London at [email protected]; Naomi Kresge in Berlin at [email protected] To contact the editors responsible for this story: Benedikt Kammel at [email protected]