German drugs and crop chemicals group Bayer AG has offered to buy U.S. seeds company Monsanto for $62 billion in cash, defying some of its own shareholders in a bid to grab the top spot in a fast-consolidating farm supplies industry.

Monsanto Co’s stock ended trading up 4.4 percent at $106 on the New York Stock Exchange on Monday, well below Bayer’s $122 per share cash offer price, in a sign that it faces a tough task convincing the St. Louis-based company to sign off on the deal.

Monsanto has said it would review the proposal. Some analysts have suggested Bayer might still have to pay more.

“The price that has now been disclosed is at the upper limit and it is just about economical. Should it rise further, which is to be assumed, the takeover will become increasingly unattractive,” said Markus Manns, a fund manager at Union Investment, Bayer’s 14th biggest investor

Other Bayer shareholders have also responded coldly to the company’s pursuit, condemned by one Bayer investor as “arrogant empire-building” when news of the proposal emerged last week.

The unsolicited proposal would be the largest all-cash takeover on record, according to Thomson Reuters data, just ahead of InBev’s $60.4 billion offer for Anheuser-Busch in June 2008.

The move would also eclipse a planned combination of peers Dow Chemical and DuPont’s agriculture units and comes just three weeks after Werner Baumann took over as Bayer CEO.

Giving details for the first time, Bayer said on Monday it would offer $122 per share, a 37 percent premium to Monsanto’s stock price before rumors of a bid surfaced.

“We fully expect a positive answer of the Monsanto board of directors,” Baumann told reporters on a conference call, describing criticism from some investors as “an uneducated reaction in the media” when deal terms were not yet known, and driven by an element of surprise.

Monsanto, which said last week it had a received an approach from Bayer but gave no details, declined to comment.

Seven of Monsanto’s top 20 investors declined to comment about Bayer’s offer when contacted by Reuters. Others could not be immediately reached for comment.

Antitrust experts see an overlap in the seeds business, particularly in soybeans, cotton and canola. Bayer’s LibertyLink line of weed killers, plus crops that are resistant to it, are an important alternative for farmers suffering from weeds that have grown resistant to Monsanto’s Roundup herbicide.