Oil giant ExxonMobil announced an alliance Tuesday with biotech firm Synthetic Genomics to make a new biofuel from photosynthetic algae.

The biggest US energy firm said it was partnering with the firm headed by Craig Venter, a researcher who founded Human Genome Sciences and Celera Genomics and has worked on projects to sequence the genomes of humans, fruit flies and other organisms.

ExxonMobil said it expects to spend more than 600 million dollars if certain milestones are reached to produce the fuel, which does not contribute to greenhouse emissions.

"This investment comes after several years of planning and study and is an important addition to ExxonMobil's ongoing efforts to advance breakthrough technologies to help meet the world's energy challenges," said Emil Jacobs, vice president at ExxonMobil Research and Engineering.

"While significant work and years of research and development still must be completed, if successful, algae-based fuels could help meet the world's growing demand for transportation fuel while reducing greenhouse gas emissions," said Michael Dolan, senior vice president of ExxonMobil.

"Our new algae biofuels program complements ExxonMobil's ongoing efforts to reduce emissions in our operations and by consumers of our products, through both efficiency improvements and technology breakthroughs."

Last month, Dow Chemical announced plans to join Algenol Biofuels in a pilot-scale project to use algae and carbon dioxide to produce ethanol fuel.