 Shares of Western Digital Corp. S: WDC were surging 10 in premarket trading Tuesday after Elliott Investment Management called for the company to split its business in two and offered at least 1 billion in capital to help with a separation. Elliott issued a letter to Western Digitals board of directors saying that while the company has great potential in both its hard-disk drive and flash businesses, it has underperformed-operationally, financially and strategically. 