Monsanto Co. (MON) on Thursday announced more job cuts and said profits from its crop-protection unit would fall more than expected.

The world's largest seed company by revenue said intensifying competition faced by its Roundup herbicide would leave full-year earnings at the low end of its existing guidance. Its first forecast for fiscal 2010 fell well short of analysts' expectations.

Roundup had been a moneyspinner that chief executive Hugh Grant once called a "windfall" to fund research into its core business of seeds and traits.

However, competition from generic crop-protection products, notably from China, have weighed on sales and margins.

The company plans to double previously-announced job cuts to around 8% of its global workforce - some 1,800 jobs - from the 900 indicated in June.

Monsanto will boost a restructuring reserve to a range of $550 million to $600 million as part of cost-cutting efforts aimed at trimming $220 million to $250 million from annual expenses. It plans to realize a third of this in fiscal 2010 and the full target from 2011.

Monsanto said ongoing earnings per share for fiscal 2009 would be "at the low end" of its previously-announced range of $4.40 to $4.50, with lower-than-anticipated earnings from herbicides outweighing "slightly" higher gross profit from seeds and traits.

Its shares were down 5.5% at $78.90 in early trade.

The company issued the guidance in a statement ahead of a conference presentation from chief financial officer Carl Casale in London.

The U.S. company's first indication for fiscal 2010 - with ongoing EPS forecast at $3.10 to $3.30 - compared with the $4.10 consensus among analysts.

Casale warned in a statement that tough competition from generic herbicides created "multiple headwinds" in its goal of securing $1 billion gross profit from the segment by 2012. Profits from Roundup and its other herbicides are forecast at $650 million to $750 million in fiscal 2010. In June, the company said it would earn $1 billion from the range, half their recent peak.

However, Monsanto retained its pledge to double gross profit by 2012 from a 2007 base as it rolls out new genetically-modified corn and soybean seeds.

-By Doug Cameron, Dow Jones Newswires; 312 750 4135;

doug.cameron@dowjones.com