Drug and chemicals giant Bayer AG made an unsolicited takeover offer for agrichemicals behemoth Monsanto Co., both companies said in separate statements, confirming ongoing speculation. Details of the negotiations and the proposed deal were not made public, but a merged entity would be the world’s largest seed and agrichemicals company, with a combined market cap of about $130 billion.

Monsanto issued a statement Wednesday “in response to recent media reports” to say “it has received an unsolicited, non-binding proposal from Bayer AG for a potential acquisition of Monsanto, subject to due diligence, regulatory approvals and other conditions.”

The St. Louis, Missouri, company said the proposal was being reviewed by its board of directors and that it will make no further comment until the review is complete. “There is no assurance that any transaction will be entered into or consummated, or on what terms,” the short statement added.

Following Monsanto, Bayer also issued a brief statement Thursday saying its “executives recently met with executives of Monsanto to privately discuss a negotiated acquisition of Monsanto Company. The proposed combination would reinforce Bayer as a global innovation-driven Life Science company with leadership positions in its core segments, and would create a leading integrated agriculture business.”

The colossal entity that would be born from the planned merger of these two companies would deal in a range of products from antibiotics and pesticides to genetically modified seeds for crops. At present, agriculture accounts for about 22 percent, or a fifth, of the German company’s revenue.

Monsanto has a market cap of over $42 billion, while Bayer’s market cap stands close to $90 billion. The industry has seen two big merger deals recently, which are still undergoing regulatory reviews in the United States. One was the acquisition of Swiss agrichemicals company Syngenta AG by China’s state-backed ChemChina for $43 billion. The other was the planned $130 billion all-stock merger deal between DuPont and Dow Chemical, announced in December.

Monsanto had made an unsuccessful bid for Syngenta in 2015, and earlier this year, had approached Bayer for the latter’s crop sciences business.

Shares of Monsanto fell by 0.6 percent during Wednesday trade on the New York Stock Exchange, and fell another 0.34 percent after hours, while the NYSE Composite Index fell by 0.18 percent. Bayer shares, traded on the Frankfurt Stock Exchange, fell 6.59 percent on Wednesday, compared with the broader DAX Index that fell 1.02 percent.