ISTANBUL, Aug 28 (Reuters) - Turkish lender Isbank's decision to demerge frees up its subsidiaries to be listed in the future and allows the bank to use its equity more effectively, Chief Financial Official Gamze Yalcin said on Monday.

The bank's shares soared more than 8% to a record high after it earlier announced it would transfer shares in its subsidiaries and an affiliate to a new company, a move it said would bring about sustainable growth and investments in new fields.

Yalcin, addressing a webcast event in Istanbul, said the demerger would pave the way to boost shareholder value given what she said was an evident discount in the Istanbul-listed bank's share price.

About 75% of Isbank's approximately 150 subsidiaries were operating in the highly regulated financial sector, Deputy Chief Executive Cahit Cinar said at the same event, adding there would be more investments in the industrials sector.

"Taking increased regulation and this (high) concentration into account, we expect the new holding company will increase our concentration in the non-financial sector," he said.

Isbank's largest industrial holding is Sisecam SISE.IS, one of Europe's largest glassmakers.

(Reporting by Can Sezer and Birsen Altayli; writing by Jonathan Spicer; Editing by Sharon Singleton)