After the federal government and 17 attorneys general sued American Express for alleged anti-competitive behavior, a judge Wednesday denied the company’s bid for summary judgment.

The U.S. Department of Justice asserts American Express ran afoul of antitrust laws with so-called “anti-steering” provisions that allegedly restrained merchants from steering customers to other credit cards that had lower fees for merchants.

American Express argued that the government could not show that its practices adversely affected competitors.

But in U.S. v. American Express, 10-cv-449, Eastern District Judge Nicholas Garaufis (See Profile) said there were factual questions surrounding any adverse effects.

American Express claimed the government’s suit failed because it had to show “market power in the relevant market,” but American Express had a “low market share.” A footnote in the ruling reports that American Express in 2012 had about 26 percent of the general purpose credit and charge card volume, second to Visa, which had 44 percent.

Garaufis acknowledged market share was “an important part” of determining market power but was “not the only component.” MasterCard and Visa were also named in the suit but settled in July 2011 (NYLJ, July 21, 2011).

In a statement, American Express said it “continues to believe that it has strong defenses to the DOJ lawsuit and will defend the case vigorously.”

Evan Chesler, partner and chairman at Cravath, Swaine & Moore and Donald Flexner,a partner at Boies, Schiller & Flexner appeared for American Express.

Craig Conrath of the Department of Justice’s Antitrust Division appeared for the government and Mitchell Gentile of the Ohio Attorney General’s office appeared for the plaintiff states.