Japanese stocks fell to their lowest in more than a week on Friday, with mobile firms extending a sell-off on concerns of increased competition after e-commerce group Rakuten said it aims to become the country's fourth wireless carrier. Taking the cue from weak US stocks overnight, the Nikkei share average declined 0.6 per cent to 22,553.22, the lowest closing since December 7. For the week, the Nikkei shed 1.1 percent.

The information and communication sector slumped 3.2 per cent and was the worst performer on the board. KDDI Corp tumbled 6.7 percent, NTT Docomo skidded 4.6 per cent and SoftBank, which has a more diversified business portfolio, shed 2.4 per cent. The sell-off was triggered after Rakuten Inc said it was weighing entry into the mobile carrier market, which would set it up to compete with the telecom giants.

On the other hand, heavyweight stocks such as clothing company Fast Retailing Co rose 1.3 per cent, while chip equipment makers also gained ground, with Tokyo Electron rising 1.4 per cent and Advantest gaining 0.9 per cent. The broader Topix dropped 0.8 per cent to 1,793.47.