Oracle has completed the acquisition of Siebel Systems after Siebel shareholders officially accepted Oracle's $5.85bn offer. The acquisition makes Oracle the largest vendor of CRM software.

The firm stated that it will make Siebel's applications the centrepiece of its CRM strategy for its forthcoming Fusion application suite.

Fusion is scheduled for release in 2007 and aims to create a single application suite to which Oracle, PeopleSoft, JD Edwards and Siebel users can migrate.

Siebel shareholders have the option of a one-time cash payment of $10.66 per share or can opt to trade in their shares for Oracle stock.

The database vendor will purchase the shares in the marketplace, effectively making it an all-cash transaction.

Oracle has scheduled an investor conference call for Thursday, but did not mention any briefings or updates for users and developers.