Feb 4 (Reuters) - Agrichemicals producer FMC Corp FMC.N forecast first-quarter revenue below Wall Street estimates on Tuesday, owing to weak demand, sending its shares down over 20% in after-market trading.

The company's sales volume is expected to be lower as customers in various countries continue to reduce inventory and purchases are made cautiously by retailers and growers amid lower commodity prices, the company said.

High inventory levels of crop chemicals in multiple regions have been putting pressure on the earnings of insecticide and fungicide producers such as FMC.

FMC is one of the largest crop-protection product makers in the United States and competes with industry giants such as Syngenta, as well as German firms BASF BASFn.DE and Bayer BAYGn.DE in the agricultural chemicals sector.

The company, however, beat Wall Street's fourth-quarter profit expectations, helped by higher sales volumes, especially in the United States, and lower costs.

"While we saw a good increase in volume, the growth was below our expectations as we learned during the quarter that customers in many countries sought to hold significantly less inventory than they have historically. This dynamic, along with more pronounced FX impacts, acted as a headwind to further growth," CEO Pierre Brondeau said in a statement.

The herbicide maker forecast first-quarter 2025 revenue in the range of $750 million to $800 million. Analysts' expectations were of $963.7 million.

First-quarter adjusted earnings are expected to be in the range of $0.05 to $0.15 per share, compared to estimates of $0.83 per share.

The Philadelphia-based company posted an adjusted profit of $1.79 cents per share for the three months ended Dec. 31, compared with analysts' average estimate of $1.6 cents per share, according to data compiled by LSEG.

(Reporting by Vallari Srivastava and Mrinalika Roy in Bengaluru; Editing by Mohammed Safi Shamsi)

((Srivastava.Vallari@thomsonreuters.com;))