Toshiba Corp. investor King Street Capital Management plans to nominate a slate of independent directors to replace a majority of the manufacturer's board, ratcheting up the hedge fund's first public activist campaign.

Among the nominees will be Brian Higgins, co-founder of the fund, which manages about $20 billion. King Street owns about 5.4 percent of Toshiba and is its fourth-largest shareholder. The stock rose as much as 2.5 percent in Tokyo on Tuesday.

In a letter to Chief Executive Officer Nobuaki Kurumatani dated Monday, New York-based King Street said Toshiba needs new independent directors to "fully maximize its industrial strengths and empower the innovative potential of its employees."