Intel Corp. is jumping into the network computer market with a Pentium-based design, in an attempt to head off the host of microprocessor rivals that hope to use the network computer to cut into the Wintel duopoly.

Oracle Corp., Redwood Shores, Calif., which early this year unveiled a network computer reference platform based on Advanced RISC Machines Ltd.'s processors, will add Intel's network computer Pentium design to its stable of alternative network computer architectures, industry sources said last week. Intel is also expected to pick up several other PC makers within the next month that will use its network computer concept.

Intel's decision to fight network computer fire with fire could have major repercussions in an ill-defined market just starting to get under way. The market battle would no longer be pitting all the network computer vendors against Intel, because the chip maker and its PC customers would also be in the thick of network computer competition.

An Intel spokesman said a Pentium network computer version "isn't out of the question." An Oracle spokesman declined to comment.

The Intel network computer-targeted Pentium would be slated for the business market.

IBM Corp., software vendor Corel Corp., and Sun Microsystems Inc. are bringing out downsized network computer clients that can be deployed as low-cost, smart terminals in large corporate networks. IBM and Corel separately will sell network computer clients based on the PowerPC microprocessor, and Sun initially is using its Sparc RISC chip - both potential threats to Intel.