Nov. 18 (Bloomberg) -- Autodesk Inc., the biggest maker of engineering-design software, dropped the most in 10 months in Nasdaq trading after forecasting fourth-quarter profit that fell short of analysts’ estimates.

Excluding some items, profit will be 19 cents to 24 cents a share, the San Rafael, California-based company said yesterday in a statement. Analysts predicted 25 cents on average, according to a Bloomberg survey.

Autodesk’s customers have cut jobs and curbed plans for construction and manufacturing, crimping demand for engineering software. Designers use the company’s 2-D and 3-D modeling to create everything from buildings to Hollywood visual effects.

“The health of the global economic environment remains mixed and the continued job losses in our core markets represent ongoing challenges to a swift recovery in our business,” Chief Executive Officer Carl Bass said in the statement.

Autodesk fell $2.80, or 10 percent, to $24.20 at 4 p.m. New York time in Nasdaq Stock Market trading. The drop was the most since Jan. 15.

Third-quarter net income dropped 72 percent to $29.5 million, or 13 cents a share, from $104.5 million, or 45 cents, a year earlier, Autodesk said. Sales fell 31 percent to $416.9 million in the period, which ended Oct. 31.

Fourth-quarter revenue will be $420 million to $440 million, Autodesk said. Analysts estimated $432.6 million.

To contact the reporter on this story: Nick Turner in San Francisco at nturner7@bloomberg.net

Last Updated: November 18, 2009 16:18 EST