TORONTO -- An Ontario judge has found that the owner of a Toronto office building was responsible for the deaths of hundreds of birds that flew into its highly reflective windows.

However, the Ontario Court judge declared Cadillac Fairview acquitted of the charges because it did due diligence in trying to rectify the problem at the Yonge Corporate Centre.

Ecojustice, an environmental group that launched the court case, says it sees a partial victory because it means other building owners need to act on similar problems because the law does apply to them.

Judge Melvyn Green ruled that the company was responsible under two out of three charges, but acquitted Cadillac Fairview because it took reasonable steps to try to fix the problem, including applying film on the windows.

The two charges were under the Species at Risk Act for killing, harming or taking birds of a threatened species and under the Environmental Protection Act for emitting a contaminant -- light -- that caused the birds' death.

Green dismissed a charge under the Ontario Society for the Prevention of Cruelty to Animals Act because he wasn't convinced the section applied to wildlife.