EMERYVILLE -- Shares of Amyris jumped 4.3 percent on Wednesday, the same day that the S&P 500 Index plunged 2.3 percent.

Amyris rose primarily because the biofuels company posted a narrower third-quarter loss. The company gained 11 cents and finished at $2.70 on Wednesday.

Emeryville-based Amyris said its third-quarter loss narrowed to $20.3 million, compared to the year-ago loss of $43.7 million. Revenue fell 47 percent and totaled $19.1 million.

The Amyris technology genetically modifies bacteria to convert plant sugars into a hydrocarbon called farnesene, which can be processed into fuels or specialty chemicals. The company's products can be used in cosmetics, artificial flavors, lubricants, diesel and jet fuels.

The company's cash dwindled. Amyris had $44.4 million in cash and cash equivalents at the end of September, down from $103.6 million at the end of September 2011.

Contact George Avalos at 925-977-8477. Follow him at twitter.com/george_avalos.