* CEO Nabeel Gareeb resigns
* Names board member as interim CEO
* Shares fall 18 pct (Adds analysts' comments, details, updates share movement)
By Purwa Naveen Raman
BANGALORE, Oct 30 (Reuters) - Silicon wafers maker MEMC Electronic Materials Inc WFR.N said Chief Executive Nabeel Gareeb resigned, sending its shares down as much as 18 percent to their lowest level in three years.
The resignation comes at a time when the company has been missing market estimates for quarterly earnings, hurt by recurring manufacturing issues and weakness in the semiconductor market due to lower IT spending and oversupply.
However, not many people suspected that Gareeb, who's been one of the key persons responsible for the company's transition from a semiconductor firm to both a silicon- and solar-wafers company, would resign at this point.
"Over the past seven years, he (Gareeb) has taken MEMC from a nobody to one of the leading pre-eminent polysilicon manufacturers," Gordon Johnson II of Hapoalim Securities told Reuters.
Gareeb's biggest attribute has been the ability to execute long-term contracts with solar companies at a very aggressive pricing, which helped in building a backlog of revenues, Johnson said.
On one hand, people are sorry to see him go, on the other, there are concerns that this time too the company's outlook could be a bit aggressive, he said.
Shares of MEMC, which supplies wafers to the chip and solar industries, have lost more than 80 percent of their value since December 2007, when they touched a high of $96.08
"Looking at the stock price, it's pretty clear that the investors have lost faith in the CEO," said JP Morgan analyst Christopher Blansett.
The company implies that Gareeb feels that "may be it's time for him to move on" and look for somebody else who can lead the company and regain investor confidence, he said.
MEMC named Marshall Turner, currently a member of the board, as interim CEO, effective Nov. 12, while a search is conducted for Gareeb's permanent replacement.
Gareeb, who was appointed president and chief executive in April 2002, has agreed to assist in a transition through the end of 2008, the company said.
"I don't believe there was a succession plan, so I don't believe there's anybody who's been highlighted to take over," said Blansett, who has an "overweight" rating on the stock.
Shares of the company, whose customers include South Korea's Samsung (005930.KS) and China's Yingli Green Energy (YGE.N), were trading down 41 cents at $16.58 Thursday afternoon on the New York Stock Exchange. They touched a three-year low of $13.89 in the morning session. (Editing by Amitha Rajan)