NEW YORK (TheStreet) -- Shares of Monsanto (MON) were declining in late-afternoon trading on heavy volume Tuesday as suitor Bayer (BAYRY) said it was still in advanced negotiations to buy the seeds company for up to $127.50 per share, or a 2% increase over its prior offer in July.

Citigroup wondered if the latest offer will be enough, Barron's reports.

German-based Bayer initially offered $122 per share for Monsanto and then $125 per share, the firm noted.

"Our sense is that Monsanto shares may initially react positively to this news. However, the 2% increase in the latest proposal (and ~4.5% increase since the initial offer) may not be enough to bring Monsanto management to the negotiating table," Citi said in a note cited by Barron's.

The firm believes the deal has a 40% chance of being completed if Bayer raised its offer to $135 per share.

"The Bayer offer comes at a time when the agriculture cycle is depressed. In our view, the key question for Monsanto management is how it will convince investors and potential buyers of the unrealized value of its technology. We think short-term investors are likely to pressure management, but regulatory risks have also increased," Citi added.

More than 7.5 million of Monsanto's shares changed hands so far today vs. its average 30-day volume of 2.46 million shares per day.

Separately, TheStreet Ratings Team has a "Buy" rating with a score of B on Monsanto stock.

The company's strengths can be seen in multiple areas, such as its good cash flow from operations, expanding profit margins and increase in stock price during the past year.

The team believes its strengths outweigh the fact that the company has had somewhat weak growth in earnings per share.

Recently, TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this articles's author.

You can view the full analysis from the report here: MON