It said the riff Led Zeppelin was accused of taking from Spirit's 1967 song Taurus "was not intrinsically similar" to Stairway's opening, reported BBC online.
But it said Zeppelin singer Robert Plant had access to Taurus. Stairway to Heaven was released in 1971.
The case was brought on behalf of Spirit's late guitarist, Randy Wolfe.
During the trial, defence lawyers argued that the chord progression in question was very common and had been in use for more than 300 years.
Spirit's bassist Mark Andes testified last week he met Plant at the show and played snooker with him afterward.
