Oracle, fresh off its high-profile patent fight against Google, is heading back to court again, this time in its dispute with former partner Hewlett-Packard over the future of Intels high-end Itanium processor platform.

Jury selection at Santa Clara County Superior Court in San Jose, Calif., is scheduled to begin May 31 in the case, which stems from Oracles decision last year to end software development in support of Itanium, Intels controversial chip architecture that powers HPs high-end Integrity and NonStop server platforms.

Oracle executives have said the decision came after learning from Intel engineers that the giant chip maker was planning to end development of Itanium in favor of its x86-based Xeon server processors. Officials with both HP and Intel have disputed that claim, saying that Intels road map shows more generations of Itanium in the works over the next several years. HP is by far the largest Itanium customer.

HP executives claimed Oracles decision was a ploy to force the companies joint customers off HP systems and onto Oracles SPARC/Solaris Unix platform, which Oracle inherited when it bought Sun Microsystems in 2010. HP estimates that the two companies have about 140,000 joint customers, many of whom run their Oracle enterprise applicationsincluding database softwareon HPs Integrity servers.

HP sued Oracle, claiming the Itanium decision violated an agreement between the two to continue supporting technology used by those joint customers. Oracle officials have said there is no such ironclad agreement, and countersued HP, claiming that HP had misled customers about the future of Itanium.

Oracle became the third major enterprise software maker, behind Microsoft and Red Hat, to end support for Itanium.

The lawsuits were only the latest step in the fraying relationship between two companies that for a long time had been close partners. Holes in the partnership began to surface in 2009, when Oracle executives announced they were buying Sun, which put it in direct competition with HP in the data center hardware space.

It further eroded in 2010, when HP forced Mark Hurd to resign as CEO after questions about his personal conduct arose. It later hired Leo Apotheker as CEO. Apotheker, who lasted less than a year at HP, had been CEO of SAP, Oracles top enterprise software rival. Tensions increased when Oracle hired Hurd as president. HP sued Oracle, and the two sides eventually settled. HP officials claimed that as part of the settlement, the two companies agreed to continue supporting their joint customers. However, Oracle officials have argued that there was never a binding agreement.