Activist investor David Einhorn plans a major push against Apple Inc. (NASDAQ:AAPL) by holding a Thursday afternoon webcast to urge a vote against a bylaw change. Einhorn’s Greenlight Capital owns 1.3 million shares of Apple stock that are valued at more than $600 million.

The New York-based investor claims the bylaw change proposed for the Feb. 27 annual meeting would bar Apple from issuing preferred shares with dividends as a way of dealing with its $137.1 billion cash pile.

Greenlight also sued the Cupertino, Calif.-based company in U.S. District Court in Manhattan, and it won sympathy from Judge Richard Sullivan, who reserved a decision after hearing technical arguments on Tuesday.

Apple CEO Tim Cook last week termed the entire case “bizarre” and said management had talked with Einhorn and other investors about returning cash to shareholders. The company restored dividend payments last year and also began a share buyback.

Several major shareholders of Apple, including Calpers, the biggest state pension fund, said they will oppose Greenlight, claiming the bylaw change promotes good governance.

Einhorn said he’ll provide “additional details” about his plan, which is to have Apple issue $50 billion worth of preferred shares with a 4 percent annual dividend. They would trade like Apple common shares.

Einhorn is opposing Apple's Resolution 2 but hasn't sent materials to shareholders.

Greenlight said the call will begin at 2 p.m. EST at

Apple shares fell 51 cents to $448.34 in Thursday trading. They've fallen 15 percent this year.