Under Armour CEO touts Stephen Curry, Jordan Spieth lines amid business decline

Shares of Under Armour took a nosedive on Tuesday morning, dropping more than 15 percent, after the company reported that its sales declined 5 percent in the third quarter.

It was the company's first sales decline since it went public in 2005. Earlier this year, the company had its first operating loss.

One of the few bright spots on the company's earnings call was when Under Armour founder and CEO Kevin Plank talked about the businesses generated by endorsers such as Golden State Warriors star Stephen Curry and golfer Jordan Spieth.

"We've got a tremendous opportunity with a franchise like Curry," Plank said.

Under Armour's Curry business rose to about $200 million in sales in 2015, but faced a tough 2016 due to lack of success of the Curry 3 shoe.

"We've applied the lessons from the Curry 1, 2, and 3, and we've put them into the Curry 4," Plank said.

A limited release colorway of the Curry 4 launched in China earlier this month, with the first mass colorway launching last week in the United States.

"We're seeing incredible demand," Plank said.

Although footwear is now a $1 billion business for Under Armour, Plank said its relative size excites him.

"With only 20 percent of our business being footwear today, where it's more than 50 percent for our chief competitors, we see a massive runway of opportunity there," he said.

Plank told an analyst on the call that "our golf business is doing incredibly well." The company did not break out those sales.