The Government contended that the companies concealed more than $100 million in taxable income from oil trades.

They say the company then concealed the burning to avoid paying the Government $115,000 in royalties.

The contract had been buried deep, concealed behind numerous cover names and front companies.

Though he cited reasons of health, the company did not conceal its chagrin over the way the whole thing was handled.

Officials say the company concealed and altered reports about possible ties to organized-crime figures.

But, Ms. Rehnquist said, companies sometimes conceal the discounts they give other buyers.

The two companies have zealously concealed their technical secrets, including costs.

He kept his little company concealed in the dunes as best he could, for what it was worth.

Minnesota argues that the companies concealed the dangers of smoking.

The company concealed this information from the F.D.A., the agency said.