Google has apologized to competitor Sohu.com after its Chinese rival complained its data was used by the U.S. search leader in a new tool for entering Chinese characters.

Sohu, which controls about 6.5 percent of the Chinese search market, complained Sunday that Google's tool for inputting Chinese characters appeared to copy material from Sohu's Sogou search engine. Chinese Web surfers pointed out similarities shortly after the release of the Google tool, according to the Wall Street Journal.

"We are willing to face up to our mistake, and offer an apology to users and to the Sohu company," Google said in a statement, though no information about what exactly Google did was made available.

This isn't the first time Google has been accused of copying a competitor. Last year, Google copied a Yahoo page and passed it off as its own.