TOKYO, Jan 17 (Reuters) - Japan's Nikkei share average dropped on Wednesday as mining, oil and shipping stocks lost ground, while bitcoin-related stocks tumbled after the cryptocurrency's value extended its sharp decline on worries over tighter regulation.
The Nikkei dropped 0.4 percent to 23,868.34.
The mining, oil and shipping sectors underperformed, losing their recent strength by falling 1.3 percent, 2.8 percent and 1.1 percent, respectively.
Inpex Corp slipped 1.2 percent, Showa Shell Sekiyu dropped 2.6 percent and Mitsui OSK Lines shed 1.2 percent.
Bitcoin extended its sharp tumble of the past 24 hours, skidding more than 7 percent on Wednesday in a rapid reversal of fortunes.
Investors were spooked by fears regulators might clamp down on the cryptocurrency that has skyrocketed in value over the past year.
Japanese virtual currency trading company Remixpoint Inc stumbled 4.0 percent, internet media planner Ceres Inc nosedived 14 percent and internet services provider GMO Internet slumped by 8.0 percent.
The broader Topix dropped 0.2 percent to 1,890.82.
Reporting by Ayai Tomisawa; Editing by Eric Meijer