San Francisco CNN Business  — 

Amazon sellers just got a little more freedom.

The e-commerce company will no longer prohibit its third-party sellers from listing their products on other sites for less than they do on Amazon’s US site.

The change comes amid concern that the stipulation, called price parity, could be in violation of US antitrust law.

Amazon (AMZN) confirmed the policy change, which took effect Monday, but would not comment on it.

Senator Richard Blumenthal had called previously on the Department of Justice and the Federal Trade Commission for an investigation into antitrust violations and how they could affect the prices that consumers pay for goods.

“Amazon’s price parity provisions may raise prices for consumers both in the short term and in the long run,” he wrote in letters to the DOJ and FTC in December. “Relatedly, Amazon’s price parity provisions may work to block the emergence of more efficient online marketplaces that might offer consumers lower prices on their favorite goods.”

In a statement to CNN Business, Blumenthal said he welcomed Amazon’s decision, but that he is “deeply troubled that federal regulators responsible for cracking down on anti-competitive practices seem asleep at the wheel, at great cost to American innovation and consumers.”

Amazon still faces scrutiny from legislators who want more regulation of large tech companies.

Senator Elizabeth Warren has called for tech companies to be broken up because they have too much power. She’s singled out s everal companies, including Amazon, and has proposed a law that would mean, among other things, that Amazon wouldn’t be able to sell its own branded products like AmazonBasics on its platform, which would mean lost revenue.

Amazon also recently backed out of its plan to build a massive campus in Long Island City, following backlash from local politicians and residents over the incentives it was receiving from the city.