IBM has signed a deal with Landmark Graphics to build Linux supercomputers and PCs for oil and gas companies, the companies will announce Friday.

Landmark Graphics, a subsidiary of petroleum industry support company Halliburton, provides software for oil exploration, drilling and production. Under a three-year deal, IBM will cooperate with the company to bring these products to Linux systems. IBM will provide service and support for the products.

The deal is part of the gradual spread of Linux to servers and specialty markets, posing a threat to companies such as Sun Microsystems and Microsoft.

Under the deal, IBM and Landmark Graphics will provide Linux for 3D desktop and mobile graphics programs as well as groups of servers joined into a "cluster" to run supercomputing applications, the companies said.

The companies didn't disclose terms of the deal.