TOKYO, July 20 (Reuters) - U.S. hedge fund Elliott Management has raised its stake in Japan’s Alpine Electronics Inc to 6.3 percent, a regulatory filing showed, less than a week after it said it could make “significant proposals” to the components maker.

Elliott said last week that it had taken a 5.12 percent stake in the company, a move that came after Hong Kong-based activist fund Oasis Management objected to the components maker’s sale to a larger affiliate Alps Electric Co.

Elliott was not immediately available for comment. A spokesman for Alpine declined to comment.

Activist investors are increasingly targeting Japanese companies over low valuations and cross-shareholdings. Though shifts in corporate governance are underway, some investors criticise Japanese firms for putting employee welfare and traditional practice above shareholder returns.

Oasis, which holds a near-10 percent stake in Alpine, has argued that the company’s board was allowing it to be sold too cheaply to Alps.

Oasis has struggled to persuade management and other investors on the issue, and its proposal was voted down at Alpine’s annual general meeting in June.

The rise in activism has seen Japanese companies turn to investment banks and public relations firms for advice on dealing with potential approaches by activist investors, suggesting a shift is underway in Japan Inc’s attitude towards such investors.