Bayer announced late Monday, Sept. 5, that it was still in "advanced negotiations" to acquire agrochemical giant Monsanto (MON) for up to $127.50 per share, a 2% increase over the bid Monsanto rejected in July.

Bayer said in a statement that the "key terms and conditions" of the latest proposals "have not yet been agreed."

The announcement follows reports Sunday in German newspaper Rheinische Post that the German pharmaceutical company's board will meet on Sept. 14 to assess whether to launch a hostile bid. Monsanto rejected a $125 per share offer, which valued the company at $64 billion, on July 19. The first unsolicited offer came May 19.

Bayer said in May that the proposed transaction would generate synergies of $1.5 billion after year three, increase its earnings per share by midsingle-digit percentage points in the first year and double digits thereafter. The acquisition, the proposed buyer claimed, fits with Bayer's overall position as a "life science company," and would complement its portfolio of pharmaceuticals, consumer health and animal health operations.

Jefferies International analysts have previously warned that financing may be a problem, as "Bayer's balance sheet is already stretched," including combined net debt and pension liabilities of €30 billion ($33.5 billion) at the end of the first quarter.

TheStreet previously reported that Monsanto CEO Hugh Grant was probably looking for a bid of $131 per share to $135 per share, or $67 billion to $69 billion, likely out of reach for Bayer's conservative management.

Monsanto is set to release its fourth-quarter results on Oct. 5, which will likely disappoint investors, as the U.S. Department of Agriculture said on Aug. 30 that U.S. farm net profit will likely fall 11.5% this year from 2015.

The St. Louis-based target is one of several agribusinesses to lately face a takeover offer. U.S. security regulators recently approved China National Chemical's $45 billion acquisition of Swiss chemicals giant Syngenta (SYT) , which was announced on Feb. 3. DuPont  (DD - Get Report) and Dow Chemical (DOW) agreed to a $130 billion merger last year which would split the two companies in three.

At the end of August, Sen. Chuck Grassley (R-Iowa) announced that the Senate Judiciary Committee would hold hearings investigating the proposed wave of agribusiness consolidation. Grassley told The Wall Street Journal in May that he was concerned about "the sale of too much of our food industry, especially when government-controlled entities like ChemChina are the buyers."

Despite Grassley's misgivings, Department of Treasury's Committee on Foreign Investment in the U.S. already approved the Syngenta deal, which next faces scrutiny from the antitrust officials at the Department of Justice.

Bayer's Frankfurt-listed shares fell 0.73%, to €94.24, in Monday trading. Monsanto shares closed Friday at $107.44, up 0.54%, and ticked up 0.10%, to $107.55, in after-hours trading Monday evening.