The decision Friday is a significant blow to the 7-year-old tax, which lawmakers adopted to replace what was considered an outmoded and inefficient way of taxing businesses.

The court ruled 6-1 that the Commercial Activity Tax can still be applied to revenue of companies that make money selling fuel, but the money can't go into the state's general fund.

Builders, contractors, construction companies and engineers had sued over the tax. They said Ohio voters have repeatedly rejected the notion of diverting taxes raised from fuel sales to non-road work.

The court in 2009 upheld the tax when applied to grocery store food sales.