The mixed ruling in Delaware's Chancery Court gave no clear victory to either of the companies, whose relationship turned from cozy to competitive and ended up in court in 2008.

Still to be litigated is a lawsuit Craigslist filed in San Francisco against eBay alleging its larger rival used its board seat to glean confidential information about the classified ad business.

EBay sued its smaller rival in 2008, claiming a rights plan Craigslist adopted diluted eBay's stake from 28.4 percent to 24.85 percent.

"More fortunate than Goliath, eBay leaves this field with only a gash across its forehead; less fortunate than David, Craigslist leaves this field with something less than total victory," wrote Chancellor William Chandler III of Delaware's Court of Chancery in his opinion.

EBay, which has estimated Craigslist's value at several billions of dollars, has always maintained that the courts would reinstate its true stake.

Craigslist, meanwhile, has been anxious to protect its decision-making and trade secrets after eBay launched a competing ad site, and Thursday's ruling will keep eBay out of the classified company's boardroom.

EBay claimed victory in a statement released on Thursday which did not mention the board seat.

"EBay brought this suit to protect its own shareholders and preserve its valuable investment in Craigslist," it said.