A California court on Wednesday ordered Oracle to continue porting its software to the Intel Itanium chips used by Hewlett-Packard in a number of its servers.
Last year, Oracle, which competes with HP in the hardware market but shares many customers with the vendor, announced it would cease supporting Itanium.
HP filed suit in June 2011, maintaining that Oracle was contractually bound to continue supporting Itanium.
"This case causes the Court to revisit the centuries-old issues of whether a contract exists, and if so, what does it mean," Judge James Kleinberg wrote in his decision, filed Wednesday in Superior Court for the County of Santa Clara.
HP sued its former CEO Mark Hurd after he took a job as co-president of Oracle in September 2010, arguing he held trade secrets that could hurt HP competitively.
Oracle and HP quickly negotiated a settlement agreement, but since then the companies have sharply disagreed over whether some of the verbiage drafted in it amounted to a binding contract between Oracle and HP over continued Itanium support, leading to HP's June 2011 suit.
"For approximately three decades, these corporate giants dealt on an informal basis," Kleinberg wrote in his decision. "Even when the financial consequences were in the billions, they shared resources, worked together, supported mutual customers, and with only a handful of exceptions did so without a written contract."
HP had "every reason to believe" the settlement agreement "was consistent with 'business as usual,'" Kleinberg added.
Overall, Oracle's statements amounted to a valid contract and the company is required to continue porting its products to HP's Itanium servers at no cost to HP, the judge ruled.
Those products constitute the list of software products that were offered on HP Itanium platforms as of Sept. 20, 2010, "including any new releases, versions or updates of those products," Kleinberg added.
Oracle is obligated to continue the ports until HP stops selling Itanium-based servers, the judge wrote.
"Last March, Oracle made an engineering decision to stop future software development on the Itanium chip," Oracle said in a statement. "We made the decision as we became convinced that Itanium was approaching its end of life and we explained our rationale to customers. Nothing in the Court's preliminary opinion changes that fact."
Oracle plans to appeal the judge's ruling. It has 15 days to do so, according to the ruling.