US biotech company Monsanto has reported a first-quarter profit, compared to a year-ago loss, but said operating results fell on lower US sales of herbicides and seeds. The St Louis-based company, which makes Roundup herbicide and bioengineered seeds, reported net income of US$60m, or 23 cents a share, compared with a loss of $1.74bn, or $6.59 a share, in the previous year.