The world's biggest seed maker Monsanto Co. said Wednesday (Jun 30) its fiscal third quarter net income dropped 45% on declining herbicide sales.

Monsanto said cheaper, generic versions of its Roundup herbicide continued to eat into its results.

As Roundup sales have flagged, Monsanto has accelerated its long-term strategy to shift its business from chemicals and herbicides to genetically altered seeds. But the declines in Roundup have been surprisingly steep, the company has said, as generic competition from China has expanded.

The St. Louis company said its net income dropped to US$384 million, or 70 cents a share in the quarter ended May 31, down from US$694 million, or US$1.25 a share, a year ago.

Analysts had been looking for a profit of 79 cents per share, according to a survey by Thomson Reuters.

Revenue fell to US$2.96 billion from US$3.16 billion a year ago. Analysts expected revenue of US$3.17 billion.

Sales in Monsanto's agricultural productivity unit, which includes Roundup, fell 34% to US$600 million in the quarter. Seeds and genomic sales, by contrast, rose 5% from the same period last year.

Corn seed sales remained flat at US$1 billion, while soy sales rose 2% to $549 million.

Monsanto shares slipped 51 cents to US$46.83 in premarket trading.