EBay Inc. sued Craigslist on Tuesday, alleging the classified site unfairly tried to dilute the online auctioneer’s stake in it.

EBay purchased a 28 percent stake in privately held Craigslist in 2004 from an unnamed former executive. The financial terms of the deal were not disclosed.

But in January, eBay says, Craigslist’s board, consisting of founder Craig Newmark and Chief Executive Jim Buckmaster, unilaterally acted to dilute eBay’s economic interest in Craigslist by more than 10 percent.

EBay spokeswoman Kim Rubey declined to say what eBay’s stake is now.

The company is asking Delaware’s Court of Chancery to negate the board’s actions.

The complaint is under seal because of confidentiality restrictions, according to a company statement. Craigslist may ask the court to make the complaint publicly available, eBay said.

Craigslist spokeswoman Susan MacTavish Best said the company would likely post a response later Tuesday on its Web site regarding the lawsuit.