That's the day a shareholder's resolution to break up the 138-year-old conglomerate will be put to a vote at the annual shareholders' meeting outside the company's headquarters in Leverkusen, Germany.

FORBES: A headache in Leverkusen

The pullback in the Nikkei on Thursday started with modest declines that picked up steam after Tokyo's lunch break, with stocks finishing the day at the session low, for the index's biggest one-day retreat in two years.

WSJ: World Shakes Off Nikkei's 7.3% Plunge