The company expects the savings from splicing the two businesses together will amount to $1.2 billion (1.03 billion euros) per year from 2022 onwards.
That's short of the $1.5 billion trumpeted by executives when the merger plans were inked in September 2016.
Nevertheless, “I'm convinced that this acquisition has very great potential for creating value,” chief executive Werner Baumann told investors at the group's annual general meeting in Bonn.
Bayer has been forced by competition authorities including the European Commission to sacrifice existing activities in seeds and pesticides worth 7.6 billion euros to home-grown rival BASF in exchange for approval of the Monsanto deal.
That means there will be less overlap and fewer savings when Bayer assumes the US firm's product range of genetically-modified seeds and compatible pesticides.
The German firm needs to find some 44 billion euros in new cash — from borrowing and issuing new shares — to fund the $62.5-billion Monsanto takeover, German business daily Handelsblatt calculated Friday.
Lower savings from the merger will then mean less funds available to pay off the new debts.
“Bayer will indebt itself massively over Monsanto. But it's manageable if the agrochemical division plus Monsanto turns into the promised cash machine,” Handelsblatt judged.
Executives hope the one remaining major green light will come from the US Department of Justice before a June 14th deadline, after which Monsanto could withdraw from the deal if the needed approvals have not been secured.
“We anticipate being able to close the acquisition of Monsanto in the near future,” Baumann insisted.
Some 200 people demonstrated against the Bayer-Monsanto merger outside the AGM Friday, including a woman wearing a wedding dress and a skull mask holding a sign warning of a “deadly wedding” between the two firms.
“We can't allow gigantic companies to have control over our food system,” said Christian Rollmann of protest group “Wir haben es satt” (We're fed up).