Sun Microsystems shareholders filed three separate lawsuits last month in an effort to halt the company's pending sale to Oracle, according to a filing Sun made with the US Securities & Exchange Commission on Friday.
The suits name Sun, some of its officials and Oracle as defendants, according to the filing.
All three actions are aimed at blocking the $7.4bn sale, alleging the price tag is "unfair and inadequate". They also allege "claims for breach of fiduciary duty against the individual defendants and for aiding and abetting a breach of fiduciary duty against the corporate defendants," the filing states.
The defendants have yet to file answers to the complaints, according to Sun. More information about the lawsuits wasn't immediately available on Friday.
Oracle announced its plans to buy Sun in April, after reported talks between IBM and Sun fizzled out.
Sun also said in the filing that it may have broken the US Foreign Corrupt Practices Act during fiscal 2009. The law is meant to stop companies from bribing foreign officials. Sun said it has started an independent probe into suspect activities in a "certain foreign country" and "took remedial action", as well as made a voluntary disclosure to US authorities.