For a second time, Oracle extended its bid Wednesday to acquire billing and revenue management software vendor Portal Software, given that the deal has yet to win the wholehearted support of Portal shareholders.Database and applications vendor Oracle publicly announced plans to purchase Portal for US$4.90 per share on April 12, valuing the company at about $220 million. That original offer expired May 22, and Oracle renewed the bid with an expiry date of June 6 at 12 a.m. EDT. Oracle has now extended the same offer for a second time with an expiry date of June 20 at 12 a.m.As of midnight June 6, around 23.2 million Portal shares had been tendered for the Oracle offer.Portal tried to nudge its shareholders to accept the Oracle offer last week when it issued an investor slide presentation providing more details of why the Portal board decided a sale to Oracle was the company\u2019s best bet. Portal was delisted from Nasdaq last year, and the company\u2019s management and Oracle executives maintain that Portal\u2019s continued financial viability as a stand-alone firm is in question.Although the purchase has yet to close, Oracle has already stressed the importance of adding Portal\u2019s software to its portfolio as a way for Oracle to gain more business with communications and media companies.Portal\u2019s second-largest shareholder, Berggruen Holdings North America, which holds a 9.1 percent stake, has been very vocal in its disapproval of the Oracle deal. It has fired off a string of letters to Portal President and Chief Executive Officer David Labuda. The Berggruen argument is that Portal has tried to rush through the sale of the company to Oracle at a knock-down price.In his latest missive to Labuda, dated June 1, Joshua Horowitz, director of research at Berggruen, criticized Portal\u2019s decision to issue the investor slide presentation, describing it as "an after-the-fact, self-serving attempt to induce investors to tender at an inadequate price" and "another attempt to frighten and coerce stockholders."-China Martens, IDG News ServiceCheck out our CIO News Alerts and Tech Informer pages for more updated news coverage.