Company: Nomura Holdings Inc ADR

World stock markets were pummeled Monday by election results in Greece and France that heightened uncertainty about Europe's ability to solve its debt crisis.

Shares of Japan's Nomura Holdings fell on Thursday after sources told Reuters an employee at the brokerage was the source of a tip-off to a Japanese fund manager penalized for insider trading ahead of a stock offering by energy firm Inpex. 

Moody's Investors Service cut its debt rating on Nomura Holdings by one notch to just one level above speculative or "junk" grade, an expected move that could hamper the revival efforts of Japan's top investment bank.

Moody's warned on Thursday it may cut the credit ratings of 17 global and 114 European financial institutions in another sign that the impact of the euro zone government debt crisis is spreading throughout the global financial system.

Japan's largest brokerage Nomura returned to profit in the last quarter thanks to a big revenue increase in its fixed income and equities units.  But the lender remains vulnerable to a possible credit downgrade by Moody's.

The exit of Jasjit Bhattal, the highest-ranking ex-Lehman executive at Nomura, marks a crucial juncture for the brokerage as it decides whether to now hire a global banker to push expansion, or a local to focus on Japan.

Standard & Poor's Ratings Services cut the ratings on five Australian banks on Thursday as a result of major changes in the criteria it uses to assess risk.

Nomura Holdings, Japan's largest investment bank, has cut its exposure to Italian government bonds and other Italian securities to $467 million from $2.82 billion in less than two months to reduce its risk in the region's debt crisis.