UPDATE 1-Elsztain eyes investment in IDB Holding parent

* In talks over $25 mln to $100 mln investment

* Could buy up to 30 pct stake in Ganden

* IDB Holding shares up 3.7 pct (Adds details, background)

TEL AVIV, Sept 19 (Reuters) - Argentinian businessman Eduardo Elsztain has agreed in principle to invest up to $100 million in Ganden Investments, the parent company of debt-strapped Israeli conglomerate IDB Holding Corp.

Israeli media have been reporting in recent days that Elsztain was set to buy a stake in Ganden Investments, the private company through which IDB Chairman Nochi Dankner controls IDB.

The investment would provide much-needed cash for IDB, which has been selling off assets in recent months to reduce its hefty debts. This month it reported a huge second-quarter loss that raised concerns that it may not be able to pay its debts and included a "going concern" warning in its quarterly results.

An IDB statement on Wednesday said that there are advanced talks for an investment to be made by an entity controlled by Elsztain and that the amount invested would be $25 million to $100 million, which would buy a 10 percent to 30 percent stake.

Shares in IDB Holding, which had been temporarily halted pending the company's announcement, were up 3.7 percent in midday Tel Aviv trade.

Elsztain is chairman and chief executive officer of IRSA , Argentina's biggest real estate company. He also serves as chairman of Cresud , a major agriculture producer with 35 farms and 1 million hectares under management in Argentina, Brazil, Paraguay and Bolivia.

The IDB group controls Cellcom, Israel's leading mobile phone operator, supermarket chain Super-Sol and Clal Insurance. Its subsidiary Koor Industries owns a 2.3 percent stake in Credit Suisse. (Reporting by Tova Cohen; Editing by Steven Scheer and David Goodman)