Nitto Denko Corp., the world's largest maker of optical films used in liquid crystal display panels, said demand from smartphone manufacturers is helping it mask a slump in sales to television makers.

Sales climbed in November at a similar pace to the 21 percent growth posted in October, President Yukio Nagira said in an interview at the company's headquarters in Osaka on Monday.

Precise November data, expected to be the seventh consecutive increase, will be announced Wednesday.

"The sales flow has been good, thanks to smartphones and tablet computers," Nagira, 64, said.

Nitto Denko's shares reached their highest level since June 2011 on Monday as manufacturers such as Apple Inc. boosted sales of smartphones, increasing demand for optical films that help users input data using touch panels.

The company, whose customers include Sony and Sharp, also plans to expand its medical and industrial-tape businesses, Nagira said.

"There's room for Nitto Denko to spur sales on rising demand for smartphones," said Mitsuo Shimizu, an analyst at Iwai Cosmo Holdings Inc. "The company manages to grow even when the environment isn't good."

The company, which will celebrate its 100th anniversary in 2018, produces LCD optical films that also help produce brighter and clearer images.