Sun Microsystems and Intel have scheduled a press conference for this afternoon at which they are expected to announce a new partnership to fit Sun servers with Intel hardware.
The move would break one of AMD's strongest partnerships, a four-year stint as sole supplier of Sun's x86 hardware.
Sun and AMD engineers regularly trade staff to work on optimising the Solaris code for AMD's processors, and as late as last week Sun was giving no hint that a deal with Intel was in the offing.
"We have a very strong partnership with AMD," Jim Craig, software marketing manager at Sun, told vnunet.com last week.
"While Sun continues to look at what the market needs, the relationship [with AMD] is very deep. The two companies trade technology and engineering know-how. "
Sun originally became an AMD-only shop after the success of the Opteron server processor, and the relative failure of Intel's rival Itanium processor.
Sun chairman Scott McNealy publicly referred to the Itanium as "Itanic", after its failure to excite interest in the market.
The company is now expected to announce that it will begin offering Intel's Xeon processors on its x86 Solaris servers by the middle of the year. In return Intel engineers will work on optimising the Solaris operating system for Intel hardware.
The move fits with both companies' strategies of pushing virtualisation technology as a way of cutting hardware and power costs, as well as reducing development times, since coders can run developer and management systems side by side.