NEW YORK, United States — A federal judge has rejected Adidas AG's effort to block Skechers USA Inc from selling athletic sneakers that it said copied its "Springblade" concept.

In two decisions this week, US District Judge Michael Simon in Portland, Oregon said Skechers did not wilfully infringe two Adidas patents by selling its less expensive "Mega Blade" sneakers, and denied Adidas' request for a preliminary injunction to halt sales.

The decisions are a blow to Adidas, which like some rivals often turns to US courts to stop rivals from selling products it considers knockoffs.

In its lawsuit last July, the German company said Skechers copied "leaf spring" elements of its Springblade midsole, meant to propel runners forward and improve performance.

It said this enabled Skechers to get a free ride on its technology without the development costs, and harmed Adidas' reputation and market share by cutting into Springblade's pricing power, "coolness" and "cachet."

Adidas had launched Springblade in 2013, at $180 a pair.

Simon, however, found no wilful infringement because Skechers began selling Mega Blade sneakers one year before the Adidas patents were issued in May 2016.

The judge also said an injunction was inappropriate because Adidas did not show it faced irreparable harm without one, or that it was likely to win the case.

"Adidas's evidence of irreparable injury is too conclusory and speculative," and the company "fails to make a persuasive showing that the Mega Blade shoe has had an appreciable adverse effect on the Springblade shoe," Simon wrote.

Both decisions are dated Monday, and the decision on the preliminary injunction was made public on Wednesday.

The judge put the case on hold so the US Patent and Trial Appeals Board could consider related issues.

Adidas and its lawyers did not immediately respond on Thursday to requests for comment.

Michael Greenberg, Skechers' president, said the Manhattan Beach, California-based company was pleased with the decisions.

"Skechers respects the intellectual property rights of other companies and has invested tremendous resources into building a brand identity by developing its own distinctive designs, not by copying others," Greenberg said in a statement.

Adidas has also sued Skechers for having allegedly copied the design for its classic white Stan Smith tennis sneakers. A trial is scheduled for April 2018, court records show.

The case is Adidas America Inc et al v Skechers USA Inc, US District Court, District of Oregon, No. 16-01400.

By Jonathan Stempel; editor: Marguerita Choy.