* Japan stocks oversold by some technical indicators
* Foreigners bought Japan stocks last week
* Buying before ex-dividend date helps-analyst
TOKYO, March 25 (Reuters) - The Nikkei share average rose on Friday, helped by gains in U.S. stocks on optimism about upcoming earnings reports, although investors will continue to cautiously monitor developments at Japan's troubled nuclear power plant.
Analysts said the overall market may get a lift as investors buy on dips, with some technical indicators showing that Japanese stocks are heavily oversold.
The Nikkei is now trading about 6 percent below its 25-day moving average at 10,115.40.
"Also, more than 60 percent of stocks on the Tokyo stock exchange's main board are trading below their book value, so it's time to buy back shares while watching problems at the nuclear plant carefully," said Hiroichi Nishi, general manager at Nikko Cordial Securities.
Foreign investors bought a net 891.0 billion yen ($11 billion) of Japanese stocks last week, capital flows data from Japan's Ministry of Finance showed on Friday.
Some analysts said that foreign buying may continue before the ex-dividend date on March 28.
The benchmark Nikkei average rose 0.9 percent, or 81.42 points, to 9,516.43. The broader Topix gained 0.5 percent to 858.07. The Nikkei is expected to trade between 9450 and 9650 on Friday, analysts said.
"There was selling pressure around the 9,500-mark yesterday, but we may see the index top this level, supported by buying by investors who want dividends," said Hideyuki Okoshi, general manager at Chibagin Securities.
Construction equipment makers were higher on expectations of reconstruction-related demand as well as higher resource prices. Komatsu Ltd rose 4.1 percent to 2,780 yen and Hitachi Construction gained 0.7 percent to 2,049 yen.
Shares in food processor Nichirei jumped 4.8 percent to 352 yen after the Nikkei business daily reported it would join forces with the Itochu group in the frozen-food business, taking on most of the lost production at a tsunami-damaged factory operated by an Itochu subsidiary in northern Japan. ($1 = 80.985 Japanese Yen) (Reporting by Ayai Tomisawa; Additional reporting by Antoni Slodkowski; Editing by Edmund Klamann)