TOKYO, April 16 (Reuters) - Japan’s Topix edged lower on Friday as gains in heavyweight chip stocks were capped by investor concerns about Japanese corporate outlook ahead of the earnings season. The broader Topix was down 0.19% to 1,955.50 by 0209 GMT, while the Nikkei index were almost flat at 29,636.41. “Investors are getting cautious about corporate outlook ahead of earnings season starting next week,” said Shingo Ide, chief equity strategist at NLI Research Institute. “Their expectations were so strong that now they are concerned more firms might follow Yaskawa Electric which didn’t meet market expectations.” Japanese major manufacturers will kick off their annual corporate earnings season next week, starting with electronic components maker Nidec on Thursday. Robot maker Yaskawa, the leading indicator on Japanese manufacturers’ earnings trend, this week disappointed investors with its profit outlook and its stock has lost more than 7% this week. Chip-related shares gained after Taiwan Semiconductor Manufacturing Ltd (TSMC), reported a 19.4% rise in first-quarter profit on strong chip demand. Advantest rose 0.57%, Tokyo Electron gained 0.84% and Renesas Electronic jumped 2.08%. Toshiba dropped 4.9% after a report that the conglomerate told its lenders that the company plans to reject a buyout proposal from private equity firm CVC Capital Partners. The largest percentage gainers in the index were Toho , up 2.41%, followed by M3 Inc gaining 2.34% and Daiwa House Industry, up 1.83%. Nippon Yusen, down 3.05%, was the largest loser on the index, followed by Tokyo Electric Power, losing 2.96%, and Hitachi Zosen, down 2.9%. (Reporting by Junko Fujita; Editing by Shailesh Kuber)