* Brokerage stocks fall on profit-taking * Nikkei and Topix in and out of positive territory * Pioneer soars on capital alliance By Ayai Tomisawa TOKYO, May 14 (Reuters) - The Nikkei share average edged down on Tuesday after rising earlier for a third day, as investors pocketed gains from the rapid pace of the latest rally, but losses were limited by ongoing optimism from the weak-yen trend. The Nikkei dropped 0.1 percent to 14,770.78 in mid-morning trade, moving away from a 5-1/2 year high of 14,849.01 tapped on Monday, seen as a reflection of natural caution after the market's recent steep gains. Brokerage stocks lost ground after soaring the previous day on expectations of much higher commission income as trading volume surged. Nomura Holdings fell 1.5 percent and Daiwa Securities dropped 1.6 percent. Struggling audio equipment maker Pioneer Corp jumped 33 percent and was the second biggest percentage gainer after saying it would form a capital alliance with NTT DoCoMo Inc and increase ties with Mitsubishi Electric Corp to improve its financial base. Exporters were mixed. Toyota Motor Corp shed 0.8 percent, Honda Motor Co dropped 0.5 percent, but Sony Corp rose 2.1 percent. "The market is short of new catalysts for now as most of the corporate earnings are out. Since we have confirmed that companies' conservative earnings forecasts for this year will be revised up, the mid-term trend should be positive," said Nobuhiko Kuramochi, strategist at Mizuho Securities. "Under the current guidance from companies, the Nikkei's resistance level is seen around 15,000." Most exporters based their foreign exchange assumptions at 90-95 yen to the dollar for the year ending March 2014, while the dollar trades around mid-101 levels. The weaker yen lifts exporters' competitiveness abroad and raises profits when repatriated. "The market expects earnings upward revisions in the fall, when prospects for the fiscal year end will be clearer. Then, the Nikkei's levels at 16,200-17,300 will be in sight," Kuramochi said. The broader Topix shed 0.2 percent to 1,229.55. Since the dollar pierced the 100 yen mark last Thursday, the Nikkei has gained 4.2 percent and is trading about 8.5 percent above its 25-day moving average. "The market is seesawing between worries about the steep rises and hopes for the government's growth strategy," said Yoshiyuki Kondo, an analyst at Daiwa Securities. "It seems like good timing to see a pause in the market." The Nikkei has gained about 42 percent this year, bolstered by expectations for the government's growth policies and aggressive monetary easing by the Japanese central bank.