India's Core Education & Technologies Ltd shares slumps as much as 47%
* A Core Education spokesman said the company had no immediate comment on the share falls.
* "Many had taken this stock as collateral to raise money. Now that the value of the stock is decreasing they have to top up margins, or the stock would be sold off," said an analyst at a domestic brokerage house.
* Core Education shares were down 37.5 percent as of 0524 GMT, bringing their losses so far this week to 76 percent and wiping out 25.58 billion Indian rupees ($472.4 million) from its market value.