Nikkei down as financials weigh, stimulus plan awaited

* Nikkei falls 1.5 pct on last day of financial year

* Posts quarterly drop of 8.5 pct, yearly drop of 35.3 pct

* Growing fear for world financials hits banks, insurers

* IHI bucks trend after sharply raising forecast

By Elaine Lies

TOKYO, March 31 (Reuters) - Japan's Nikkei stock average fell 1.5 percent on Tuesday, the final day of the financial year, with banks and insurers down on renewed worry about the health of the global financial system in the wake of European bank rescues.

Mizuho Financial Group (8411.T) lost over 4 percent in volatile trade, with overall volume moderate as investors awaited details of a fresh Japanese stimulus plan due out later in the day and a G20 meeting of rich and major developing countries later this week.

The benchmark Nikkei .N225 lost 8.5 percent for the quarter and 35.3 percent for the 2008/09 business year. It lost 27.6 percent in the previous business year.

But it gained 7.1 percent for March, a seesaw month that saw the Nikkei flirt with a 26-year low just under 7,000 before surging in a rally. It was its strongest monthly performance since April 2008, when it rose 10.6 percent.

It fell 126.55 points to 8,109.53 on Tuesday after sliding 4.5 percent the previous day, its biggest one-day percentage fall in over two months. The broader Topix fell 2 percent to 773.66.

Market analysts said the renewed worry about the financial system suggested conditions were likely to be rocky for a while.

"There's a sense that the recent bear market rebound may be over," said Koichi Ogawa, chief portfolio manager at Daiwa SB Investments.

"The biggest concern is financials in Europe and the United States, which of course were the driving force of much of the rally, along with worry about U.S. automakers."

Japanese Prime Minister Taro Aso is expected to unveil the outline of a new stimulus package, and market analysts said stocks briefly climbed on expectations for this before falling back.

"The government doesn't seem to have much of a sense of urgency in terms of steps required by the stock market," said Nagayuki Yamagishi, a strategist at Mitsubishi UFJ Securities.

"It seems that most steps will be merely a safety net and nothing more, though of course having a safety net is better than having nothing."