The Supreme People's Court upheld a lower court ruling and rejected the appeal of Qihoo 360 Technology Co, a leading antivirus software developer, in a dispute with Internet giant Tencent Inc over monopoly practices, the court said on Monday.

The initial ruling, made by the Guangdong Provincial High People's Court in April last year, said that Qihoo had engaged in unfair competition and should pay Tencent, popularly known for its instant message service QQ, 5 million yuan ($820,000) as compensation for economic losses.

"Qihoo 360 improperly took advantage of its competitor for business interests. It abused its dominant market position and should be held accountable," Xi Xiaoming, vice-president of the SPC, said during the hearing.