* Hedging settlement to begin on Aug 7
* IAG to book pre-tax capital gain of 84 million euros
* Deal will end Iberia's founding stake in Amadeus (Adds details, background and shares)
MADRID, July 31 (Reuters) - Spanish airline Iberia is selling its stake in travel technology company Amadeus, held through derivatives, to Nomura International PLC for 578 million euros ($774 million) cash, its parent company said on Thursday.
The International Airlines Group (IAG), which owns Iberia, had hedged the 7.5 percent stake in Madrid-based Amadeus in August 2012 in a move to limit the risk in the investment by locking in the value of the shares, while benefiting from any share price appreciation.
Shares in Amadeus have gained 69 percent since that time.
As part of the settlement, Iberia - a founding shareholder of Amadeus - will transfer its shares to Nomura over a period of 100 trading days beginning on Aug. 7.
IAG will gain 84 million euros before taxes on its income statement from the disposal, assuming the Amadeus share price remains above 18.15 euros during the settlement period, it said.
IAG is due to report second-quarter results on Friday before the market opens. ($1 = 0.7469 Euros) (Reporting by Tracy Rucinski; editing by Jane Baird)