U.S. Sen. Claire McCaskill plans to introduce legislation this week that would eliminate the advantage tapped by Alaska Native corporations in obtaining federal contracts worth billions of dollars.

A spokeswoman for the Missouri Democrat says the bill will be filed Wednesday or Thursday.

Spokeswoman Maria Speiser says the bill would, among other changes, strip the corporations of contracts with no monetary caps under a Small Business Administration program designed to help small disadvantaged firms.

The corporations would still be able to participate in the SBA program.

However, they would no longer enjoy the unprecedented benefits implemented two decades ago by then-Alaska Sen. Ted Stevens.