The District of Columbia has sued Amazon, accusing it of anticompetitive practices in its treatment of sellers on its platform.

The practices have raised prices for consumers and stifled innovation and choice in the online retail market, the district's attorney general alleges in an antitrust suit.

DC Attorney General Karl Racine's lawsuit against Amazon (AMZN) zeroes in on the e-commerce company's relationships with third-party sellers, alleging that Amazon's contracts prohibit sellers from offering their products at a lower price on other websites.

Racine said Amazon, the world’s biggest online retailer, controls 50% to 70% of online market sales.

Tuesday's lawsuit is the latest in string of complaints by attorneys general against large tech companies over the past year, following separate antitrust suits by numerous states against Facebook and Google. But it appears to be the first antitrust suit by an attorney general to go after Amazon.

The contract terms mean that the platform fees Amazon demands of its sellers — which are passed on to Amazon shoppers — must also be baked into the prices that shoppers see on sites such as Walmart's, Racine told reporters on a conference call. In some cases, Racine said, Amazon sellers are charged fees amounting to 40% of the total product price on Amazon.

Amazon rejected the allegations, saying the relief Racine is seeking “would force Amazon to feature higher prices to customers, oddly going against core objectives of antitrust law."

“The DC attorney general has it exactly backwards — sellers set their own prices for the products they offer in our store," the Seattle company said in a prepared statement. “Amazon takes pride in the fact that we offer low prices across the broadest selection, and like any store we reserve the right not to highlight offers to customers that are not priced competitively. “

Founded by Jeff Bezos, the world's richest individual, Amazon runs an e-commerce empire and ventures in cloud computing, personal “smart" tech and beyond.

The District's suit alleges that Amazon has violated DC's antitrust law. It does not contain any allegations that Amazon violated federal antitrust law, and Racine's office is not currently working with other federal or state officials on this suit.

(Inputs from Agencies)

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