Qihoo 360 Technology Co Ltd, the second-largest online search provider in China, denied reports that e-commerce giant Alibaba Group Holding Ltd may invest in the Beijing-based company.

Qu Xiaodong, vice-president of Qihoo and head of public relations, said speculation about the investment was "not true".

The company did not give any further comment.

Shares of Qihoo, traded in New York, surged to a seven-week high after market research company Marbridge Consulting Ltd said Alibaba and Qihoo were negotiating the terms of an investment.

"Qihoo is mulling an important partnership in the capital market," said news portal sina.com.cn, citing an unnamed executive inside the company.

Qihoo has closed the stock trading platform for its staff, according to sina.com.cn. The last time Qihoo closed the platform was in mid-2013 when the company was trying to acquire Sogou.com.