* Investors take profits after big gains over last 2 days
* Uncertainty on earning growth next financial year caps gains
* Real estate, non-banks down; banks rebound
By Hideyuki Sano
TOKYO, Feb 2 (Reuters) - Japanese shares slipped from three-week highs on Tuesday as investors locked in profits after two straight days of big gains following the Bank of Japan's decision to introduce negative interest rates late last week.
The Nikkei ended morning trade flat at 17,864.70, having fallen as much as 1.0 percent earlier in the day. It had gained 4.8 percent in the previous two sessions, hitting a three-week high of 17,905.37 on Monday.
The broader Topix fell 0.1 percent to 1,461.85.
While monetary easing by the Japanese central bank and a rebound in oil prices and other risk assets in global markets supported Japanese shares over the last two days, concerns about earnings are capping further gains.
"The expectation of solid earning growth in Japanese firms were the fundamental reason investors were buying Japanese shares. But that is increasingly uncertain now," said Hiroshi Ono, the head of equity investment at Sumitomo Life Insurance.
"The earning outlook for the next financial year (from April) may worsen if the U.S. economy is slowing down or if the Fed raises rates 3-4 times as it is saying. I suspect there will be more selling if the Nikkei rises above 18,000."
Traders noted that investors are now keen to take profits even in shares that had fairly upbeat earnings, suspecting hard times may be ahead.
One example was Fujikura, shares of which fell 5.0 percent after the company reported on Monday strong earning growth in the nine months to December but did not boost its annual guidance.
In addition, many resource-related companies have been hit by a slowdown in China while weaker sales of Apple's iPhones are hurting many of its parts suppliers.
"The earnings we have seen so far is a bit below my expectations and I suspect many people in the market feel the same way," said Soichiro Monji, chief equity strategist at Daiwa SB Investments.
Real estate shares fell 2.9 percent and non-bank shares dropped 1.4 percent after they had surged over the last two days following the BOJ's monetary easing.
On the other hand, investors continued to buy defensive shares, with drugmakers rising 2.5 percent.
Bank shares rose 1.2 percent after big falls in the last two days on concerns that negative interest rates will squeeze their profits.
Still, they are down almost 20 percent so far this year, making them the worst performer among the Tokyo Stock Exchange's 33 industry subindex. (Editing by Sam Holmes)