Japan's Nikkei opens up but soon sheds gains

(Updates with open)

TOKYO, July 4 (Reuters) - Japan's Nikkei stock average opened up on Friday but soon shed its gains, with Mitsubishi Corp (8058.T) and other trading houses up after oil hit a record over $145 while power firms and shippers fell. Komatsu Ltd (6301.T) powered higher after the Nikkei business daily said the company's group operating profit is likely to have risen 7 percent to about 85 billion yen for the April-June quarter, a first-quarter record, due to strong demand for construction equipment in emerging nations.

At 0005 GMT the benchmark Nikkei .N225 was down 0.1 percent at 13,256.19, a day after hitting an 11-day losing streak, the longest in more than half a century. The broader Topix was down 0.1 percent at 1,296.24. (Reporting by Elaine Lies)