* Nikkei erases early gains as yen regains strength
* Short-term technical signal suggests market overheated
* Foreigners' net buying of Japan stocks highest since April
By Chikafumi Hodo and Ayai Tomisawa
TOKYO, Dec 9 (Reuters) - Japan's Nikkei average edged higher on Thursday but backed off from a fresh seven-month high as the yen regained strength and a closely watched short-term technical signal suggested the market was overbought.
Keen interest from foreign investors, which has driven Tokyo equities 12 percent higher since the beginning of November, appeared to be in place, market players said. Capital flows data showed they were net buyers for a fifth straight week last week.
The Nikkei reached a session high of 10,298.25 -- the highest since May 18 -- but ran out of steam as investors sold to adjust their positions ahead of the settlement of futures and options prices on Friday.
But in a sign that Nikkei have become quite overheated, its short-term up-down ratio, which compares the number of shares that have risen against those that have fallen over a 25-day period, was now at its highest level since 1977 at around 158.27, said Yumi Nishimura, a senior market analyst at Daiwa Securities Capital Markets.
A figure above 120 is seen as overheated.
The benchmark Nikkei <
> closed the morning session up 0.2 percent at 10,253.72, while the broader Topix index < > rose 0.2 percent to 888.74.The dollar took a breather in Asian morning trade on Thursday, standing at 83.73 yen <JPY=> after reaching a high of 84.31 yen on trading platform EBS the previous day.
"The dollar's recent firmness is clearly positive for Japanese stocks, but the market needs to consolidate before extending more gains," said Koichi Ogawa, chief portfolio manager at Daiwa SB Investments.
Foreign investors' net buying of Japanese stocks reached the highest since early April at 210.7 billion yen in the week to Dec. 4, finance ministry data showed. [
]They were net buyers for the fifth straight week, bringing their total net buying to 730.6 billion yen over that period and out of the last 10 weeks they were net buyers for nine.
"Foreigners are still in a phase of raising their weighting for Japanese stocks as they have outperformed other markets over the last few months. Their buying is the key reason behind the Nikkei's strength," Daiwa SB's Ogawa said.
The Nikkei's 12 percent gain since November has overshadowed other markets, with the Dow Jones industrial average <
> rising 2.2 percent, while the Shanghai Composite Index < > fell 7.2 percent during that time.Market analysts are also bullish longer term. The Nikkei is likely to end 2011 at the pre-Lehman shock level of 12,000, according to a median forecast of 24 market participants polled by Reuters in the past week. Projections ranged from 9,200 to 14,000.
Shares in Japan's three biggest banks rallied on positive indications for the sector, including gains for their U.S. rivals as a spike in Treasury yields has made lending and trading more profitable, and for European banks as investors bet that concerns about the euro zone debt crisis will slowly abate.
Tokyo market players have also said that foreign investors may start turning their attention to financial stocks after picking up mainly exporters in the recent rally.
Mitsubishi UFJ Financial Group <8306.T>, Japan's biggest bank by assets, gained 2.2 percent to 411 yen, while Sumitomo Mitsui Financial Group <8316.T> added 2.2 percent to 2,678 yen. By the midday break the two banks already traded slightly above their average volume for the past month.
Daikin Industries <6367.T> rose 1.8 percent to 2,924 yen after Credit Suisse increased its target share price to 2,900 yen from 2,800 yen, citing its positive briefing on its China business.
But silicon wafer-maker Sumco <3436.T> fell 4.1 percent to 1,161 yen, extending losses for a second straight session, after widening its annual loss forecast. ($1=83.99 Yen) (Additional reporting by Antoni Slodkowski; Editing by Edwina Gibbs)