Peoplesoft's management and staff are fighting Oracle

In the letter, Oracle chief executive Larry Ellison said the $26 a share deal offered a "substantial premium".

He added that Peoplesoft's directors were trying to "deny" the shareholders the right to sell their stakes.

Oracle is urging the stockholders to tender their shares before the 12 March deadline.

Monopoly

The vote outcome will then be decided at the annual Peoplesoft shareholder meeting on 25 March.

Peoplesoft has already rejected the latest $26 a share deal, after previously snubbing ones for $19.50 and $16 a share, and its directors have refused to meet with Oracle.

"This is our final price, and we believe it represents a compelling value for all Peoplesoft stockholders," said Mr Ellison.

He added: "By rejecting our offer, Peoplesoft's directors have sought to deny you - the true owners of Peoplesoft - the opportunity to sell your shares to Oracle for a substantial premium in an all cash offer."

Oracle's letter to Peoplesoft shareholders comes a week after the US Department of Justice said the Government should block any takeover on the grounds that it would hurt competition in the software industry.