By Joshua Hunt
TOKYO, Feb 17 (Reuters) - The Nikkei share average extended its earlier losses during mid-afternoon trading on Wednesday after the yen broke from a fragile weakening trend, unnerving investors.
The Nikkei share average fell 2.2 percent to 15,704.21 in afternoon trading. Japan's benchmark index added 7.4 percent in a dramatic rally over the past two days, but stalled on Wednesday amid volatility in global markets and crude oil prices.
"The rally itself has been extraordinary but very thin and the failure of the yen to continue on the fairly steady path of weakening we've seen in the past couple of days has been reflected as nervousness in the Nikkei," said Stefan Worrall, director of Japan equity sales at Credit Suisse.
"It's been a very volatile two weeks and nerves are still frayed despite the fact that we're off the bottom of those extreme sessions we saw last week."
The broader Topix slid 1.9 percent to 1,272.69 and the JPX-Nikkei Index 400 declined 1.9 percent to 11,494.40.
(Reporting by Joshua Hunt; Editing by Jacqueline Wong)