SAN FRANCISCO (Reuters) - Apple Inc CEO Tim Cook called David Einhorn's lawsuit against his company a "sideshow" but said on Tuesday the board is carefully considering the star hedge fund manager's proposal to issue preferred stock, calling it "creative."

Cook, waving off claims that Apple is clinging to a "Depression-era" mentality, told investors at Goldman Sachs' annual technology industry conference in San Francisco that the board is in "very active discussions" on how to share more of its $137 billion hoard of cash and marketable securities.

David Einhorn is suing Apple as part of a wider effort to get Apple to share more of its cash pile, one of the largest hoards in the technology industry. Einhorn wants the iPhone maker to issue perpetual preferred shares that pay dividends to existing shareholders, arguing that such a vehicle would be superior to dividends or share buybacks.

(Reporting By Poornima Gupta and Edwin Chan; Editing by Gerald E. McCormick)