The deal, which is subject to shareholder approval, is expected to close in early 2006.

Oracle will maintain support for Siebel products while incorporating the company’s CRM product range into its own, says chief executive Larry Ellison.

‘This acquisition meets Oracle’s two key criteria for a large buy,’ he said. ‘It is immediately accretive and strategically sound, it makes us number one in a market where we already participate.’

Gartner analyst Simon Hayward says the acquisition gives Oracle a significant new customer base, but that it might be difficult to integrate another large company.

‘PeopleSoft was a big bite to chew, and Siebel will be the same. The more of these big bites Oracle takes, the harder it is to chew,’ he said.

The purchase of Siebel is Oracle’s ninth acquisition of a company or product in less than 12 months, and means the vendor will be supporting four CRM applications: its own, Siebel’s, and those previously provided by PeopleSoft and JD Edwards.