U.S. consumers aren’t yet demanding sustainable products, such as mobile phones made with recycled plastics, hampering companies’ efforts to go green, said Sprint Corp. Chief Executive Officer Dan Hesse.

“I wish consumers were demanding us to be greener, because they really haven’t yet,” Hesse said during The Year Ahead: 2014, a two-day conference in Chicago sponsored by Bloomberg LP. While a growing number of eco-friendly phones are being manufactured, customers aren’t asking for them, he said.

Sprint in 2009 created its first sustainable phone, a model that used less energy and featured recycled plastic. While the Overland Park, Kansas-based company is making other environmental improvements by moving customers to online billing and recycling old devices, some things are a hard sell because they don’t make business sense, Hesse said.

Sprint, which was acquired by SoftBank Corp. this year, closed down its outdated Nextel network on June 30, losing some subscribers in the process. The company reported third-quarter revenue of $8.68 billion in October, below the average analyst estimate compiled by Bloomberg. Sprint, the third-largest U.S. wireless carrier, is now working to attract new customers with an upgraded network and lower-cost calling plans.

Shares of the company fell 1.5 percent to $7.38 at 2:20 p.m. in New York. The stock had gained 35 percent this year through yesterday, while the Standard & Poor’s 500 Index rose 25 percent.