Salesforce.com Inc scored a coup by publicizing a dispute with rival Oracle Corp over something seemingly as mundane as the timing of a speech.

Controversy over the timing of a talk by Salesforce.com Chief Executive Marc Benioff erupted at Oracle's annual user's conference, where Salesforce had rented out an auditorium for the speech and space in an exhibition room to promote software that competes with products from Oracle.

The brouhaha began late on Tuesday night, when Benioff tweeted that Oracle had abruptly canceled a speech he was due to make Wednesday on cloud computing. Benioff, a one-time Oracle executive, gathered his audience anyway at a nearby hotel restaurant and gave his talk, which was widely covered by the press.

Nobody would have cared what I had to say today. They should have ignored me. Larry always taught me: Art of War, Sun Tzu. ... You're angry? Ignore the anger, Benioff told reporters, referring to Oracle CEO Larry Ellison.

A source at Oracle who asked not to be named said that Salesforce had agreed to possible scheduling changes when it rented out the venue at San Francisco's Moscone Center, the source said.

Oracle moved the Salesforce speech to 8 a.m. Pacific Time on Thursday from 10 a.m. on Wednesday to accommodate an Oracle customer event that was oversold and needed a larger venue, the source added.

Salesforce, which said it spent about $1 million to rent the venue for the speech and floor space in a nearby exhibition hall at the user's conference, is the biggest provider of software delivered via the Internet, or the cloud.

Oracle is eager to catch up as that is one of only a handful of rapidly growing areas in the technology sector.

THE CLOUD CAN'T BE STOPPED

The Benioff-Ellison rivalry is among the most closely watched in the business world, partly because it involves two of the biggest personalities in Silicon Valley.

Multibillionaire Ellison, who founded Oracle more than 30 years ago, is a flamboyant playboy known for his wit, business genius and aggressive business tactics.

Benioff, who recruited Ellison as one of Salesforce.com's early board members and later fired him, is an evangelist for cloud computing and legendary salesman who advises customers to use social media to promote their products -- which is exactly what he did when he complained via Twitter.

Oracle just canceled my keynote tomorrow. But the show must go on! Everyone is welcome to join me at Ame Restaurant tomorrow to hear about the social enterprise, he said in the tweet.

Sorry Larry, the cloud can't be stopped, Benioff said in a jibe at his former boss.

Some 45,000 Oracle customers paid to attend this year's annual conference where computer engineers, software developers and technology buyers learn about new products and features in Oracle's software and hardware for corporate data centers.

Ellison was scheduled to speak Wednesday afternoon in the convention center's keynote auditorium, which accommodates more than 10,000 people.

Salesforce.com shares ended down 0.3 percent at $117.25 on the New York Stock Exchange on Wednesday. Oracle shares rose 2.9 percent to $29.51 on the Nasdaq.