Bayer is stepping up its efforts to acquire Monsanto in a deal that could have a major impact on the crop science industry across the Triangle.

The German drug and chemicals firm increased its offer for the U.S. seed company on Thursday by $3 a share to $125, saying the move followed several weeks of private talks between the pair.

A combination would create a company with a strong presence in the U.S., Europe and Asia.

A Bayer executive said in May that if Monsanto agreed to the deal and regulators approved it then Bayer would move its Crop Science headquarters to St. Louis from RTP.

(See links with this post that provide additional coverage of the proposed merger.)

Bayer did not reveal the new offer’s valuation of Monsanto as debt obligations will have changed since the previous offer in May, which valued the American company at $62 billion.

Monsanto, which is based in St. Louis, Missouri, rejected the initial offer as “incomplete and financially inadequate.”

Monsanto acknowledged receipt of the revised bid but said in a brief statement that it wouldn’t comment further until its board of directors has reviewed the offer. It didn’t say when that might be.

Following private talks over the past several weeks, Bayer said it has “comprehensively addressed” Monsanto’s concerns and that it “is prepared to make certain commitments to regulators, if required, to complete the proposed acquisition.”

It added that it is also offering a $1.5 billion “reverse antitrust break fee” to reflect its confidence in securing a successful deal.

“We are convinced that this transaction is the best opportunity available to provide Monsanto shareholders with highly attractive, immediate and certain value,” Bayer CEO Werner Baumann said in a statement. “Bayer is fully committed to pursuing this transaction.”

The German company said its offer “fully captures the intrinsic value of Monsanto.”

It said its revised offer is 40 percent higher than Monsanto’s closing share price of $89.03 on May 9, the day before Bayer made a written proposal to Monsanto.

Monsanto shares were up 2.7 percent at $103.83 in New York trading after Bayer’s announcement.