Monsanto stood by expectations of its takeover by Bayer completing early next year, despite a caution raised by antitrust officials in Brazil over "competition concerns" in seed and agrichemicals markets.

Pierre Courduroux, the Monsanto finance director, told investors that the group was "anticipating closing with Bayer in early 2018", in a deal which will create the world's largest pesticides and seeds company.

The comments followed a statement from a committee within Cade, Brazil's antitrust watchdog, cautioning that the tie-up "generates a significant horizontal concentration".

This was allegedly particularly so in the markets for soybean and cotton seed, "since it merges two of the main competitors in the world, in an already significantly concentrated scenario".

'Bayer would become dominant'

The committee, headed by Cade's general superintendent, said that "the fact that most competitors operating in Brazil depends on these companies to obtain access to seeds' biotechnology could also harm competition".

And it flagged "competition concerns related to a market where integrated solutions are frequent", with seeds, for instance, often genetically modified to be resistant to certain herbicides, so allowing weeds to be sprayed off.

"After the merger, Bayer would become dominant in central links of the production chain of the main cultures."

'Just a normal step'

However, Hugh Grant, the Monsanto chief executive, said that the statement was "just a normal step within the review process.

"If you look at Brazil, you look at the rest of the world, we continue to be encouraged by the progress that we're making overall" in advancing the tie-up.

Cade's final decision will be made by its seven-member administrative tribunal, which has an initial deadline of mid-December to decide on the deal, although this date can be extended for 90 days.

'Banner year'

Monsanto's comments came after it unveiled results showing a 69% surge to $2.26bn in earnings for the year to the end of August, in what it said could be its "final" full year results.

Excluding one-off items – including a charge of $140m for expenses relating to the Bayer deal- earnings came in at $2.44bn, well ahead of market expectations of a $2.18bn result.

Brett Begemann, the Monsanto chief operating officer, said that "2017 was certainly a banner year for us", flagging in particular a 15.2% rise to $3.98bn in gross profit in corn seed, "driven primarily by better pricing", and a 35% surge to $1.88bn in gross profit on soybean seed.

"Our ramp year in Roundup Ready 2 Xtend soybeans saw our final US acre count at greater than 20m," he told investors.

Growth prospects

On the group's outlook, Mr Grant said that "looking specifically at the first quarter", which ends at the close of November, "we anticipate our earnings per share to be stronger than last year with growth expected to come primarily from soybean technologies and better pricing in Ag Productivity".

The group's Ag Productivity division includes products such as Roundup, the glyphosate weedkiller, which was seeing price rises.

"Looking beyond the first quarter, we will refrain from specifics as we anticipate closing on the merger with Bayer at the beginning of the new year," Mr Grant said.