* Hitachi up on higher operating margin forecast * Machinery data suggests companies' risk averse stance - analyst By Ayai Tomisawa TOKYO, May 17 (Reuters) - The Nikkei share average fell for a second day on Friday as caution over the recent steep rises continued to spur profit-taking while a pullback in Wall Street soured investor sentiment, but ongoing optimism in the benefits of a weak yen kept the index near the 15,000 mark. The Nikkei shed 0.3 percent to 14,992.83 in mid-morning trade, moving away from a 5 1/2-year high of 15,155.72 tapped Thursday. Also limiting the losses is strong machinery orders released in the morning, in which core machinery orders jumped a bigger-than-expected 14.2 percent in March, the quickest monthly pace in eight years. The Topix gained 0.3 percent to 1,248.65. But investors remained cautious as manufacturers expect core orders to fall in the second quarter, reflecting companies' management's risk-averse stance on capital spending. "For the time being, although sentiment for the long-term remains upbeat, companies' conservative stance on investment is souring the mood. And a pullback is not surprising given the steep rises recently and weak overseas stocks," said Toshihiko Matsuno, senior strategist at SMBC Friend Securities. Exporters were weak, with Sony Corp falling 2.3 percent, Honda Motor Co shedding 0.7 percent and Panasonic Corp sliding 1.6 percent. But Hitachi Ltd bucked the weakness, rising 2 percent after saying that it will expand its global workforce over the next three years, while aiming to boost its annual operating profit margin to more than 7 percent from 4.7 percent. Analysts said that investors will stay on the sidelines and refrain from taking large positions before the weekend. U.S. stocks fell on Thursday when a Federal Reserve regional president said the central bank could begin easing up on its monetary stimulus this summer. The Nikkei has risen around 6 percent since the dollar punched through the 100-yen mark last Thursday, which has prompted some profit-taking. The yen last traded at 102.32 to the dollar.