SAO PAULO, Nov 10 (Reuters) - Brazilian cotton producers took the natural fiber to the runway on Thursday night, strutting the catwalk of Sao Paulo Fashion Week (SPFW) in celebration of the 150th anniversary of jeans.

The fashion show, organized by the Sou de Algodao movement, showcased models wearing 40 outfits made from denim, the cotton-based material now synonymous with jeans.

Paulo Martinez, a Brazilian fashion icon who styled the show, pointed out that Brazilian cotton is "indispensable" in the manufacturing of the denim garments.

Brazil is just 400,000 bales away from overtaking the United States as the largest global cotton exporter in the 2023/24 harvest, according to USDA data, and will finish this season as the third-largest global producer, behind China and India.

More important than the race to come out on top is to show the industry and consumers the quality of Brazil's product, said the president of the Brazilian Cotton Producers Association (Abrapa), Alexandre Schenkel.

The country tracks more than 80% of its production based on environmental and social criteria with the ABR certification, which includes a QR code on the clothing label of some national brands, allowing the cotton to be traced to its farm of origin.

For Schenkel, the runway showcased the fruits of designers' labor.

"It was their harvest," he said. "And everyone in the cotton chain is celebrating something I like - jeans. Who doesn't have a piece of denim in their closet?"