Bayer AG (BAYRY) shares traded lower in Frankfurt Wednesday after the drugmaker posted solid full-year earnings but said its crop sciences unit would only see modest growth in 2017 as it completes its $66 billion takeover of Monsanto Co. (MON)

Bayer said group sales rose 1.5% to €46.8 billion last year against net income of €4.5 billion and core earnings per share of €7.32 per share. However, the Leverkusen-based group said it sees a "volatile" environment for the world seed and crop protection market next year and mid single-digit earnings growth for the company overall.

Bayer shares fell around 2.3% at the start of trading in Frankfurt to change hands at €106.4 each, trimming the three month gain to around 16%

The company also said it expects to close its $66 billion acquisition of Monsanto before the end of the year and that it had made "progress in the necessary antitrust proceedings and has already applied for clearance from some two-thirds of around 30 authorities" in order to close the deal.

"Transactions of this magnitude don't necessarily go smoothly," said CFO Johannes Dietsch. "The fact that we were so successful in these financing activities is also evidence of Bayer's good reputation in the capital markets."

Bayer said it sees sales of around €37 billion in its life sciences division this year, which it says "corresponds to a mid-single-digit percentage increase on a currency- and portfolio-adjusted basis. EBITDA before special items is forecast to rise by a mid- to high-single-digit percentage."

Pharmaceutical sales are expected to come in at €17 billion in 2017, up 3.6% from the previous year, with EDITDA increasing by a "high-single-digit percentage", the company said.

Crop science sales are forecast to be little changed in 2017 after the group moved around €9.9 billion last year. "This corresponds to a low-single-digit percentage increase on a currency- and portfolio-adjusted basis. EBITDA before special items is expected to come in on the level of the prior year," the company said.