Corporate tax reform must be revenue-neutral because raising new revenue from businesses in light of global competition "isn't realistic," Treasury Secretary Timothy Geithner said in an interview with the Wall Street Journal.

"We can't expect to raise significant additional revenue from business, as a share of GDP, from the corporate tax without hurting our competitive position, without hurting growth. It isn't realistic," Geithner said in the interview.

"We can't raise taxes on individuals to lower business taxes."

In his State of the Union speech on Tuesday, President Barack Obama called for lawmakers to help him cut the corporate tax rate while closing loopholes.

Among the business tax benefits Obama wants to scrap are those letting companies defer taxes on income earned abroad.

Geithner would not say whether the administration would propose such a move. But he said a "level playing field" was a major goal, the Wall Street Journal said.

Geithner also said it was worth looking at enterprises that are taxed as individuals rather than corporations.

"A lot of people have suggested that we look at business income generated outside what we call the corporate sector," he said. "There is a lot of income there and many of the distortions in the corporate sector affect them too."

While Republicans and Democrats agree the top 35 percent corporate tax rate is too steep, they clash over how to fund a rate cut. Obama on Tuesday repeated his position that any cut must be offset so as not to inflate the deficit.

In the interview, Geithner said the reform effort was still in the early stages and that the administration wanted to hear ideas from both Democratic and Republican leaders.

"We're in the first inning. We're going to keep consulting, with key committee chairman, with ranking (senior) members, with other stakeholders," he said. "Everybody who looks at the current system says: 'We can do better than this'. And there's a lot of interest in doing it."