SanDisk has rejected an unsolicited takeover bid from hardware maker Samsung Electronics, saying that it undervalues the Milpitas, California, maker of flash storage cards. The two companies had been in takeover talks for about four months, but Samsung went public with its offer Tuesday, apparently after discussions had broken down. "Our offer insulates your shareholders from the risk of market conditions that have severely deteriorated and are expected to remain challenging," Samsung Vice Chairman and CEO Yoon-Woo Lee wrote in a letter to SanDisk executives that Samsung released Tuesday. SanDisk Chairman and CEO Eli Harari responded quickly, saying in a...