SEOUL (Reuters) - South Korean prosecutors charged the daughter of the chairman of Korean Airlines on Wednesday for delaying a flight following an outburst over the way she was served nuts, in a case that stirred public outrage and ridicule.

Heather Cho, a former executive of the airline and head of in-flight service before she resigned, had demanded the chief steward be removed from the flight at John F. Kennedy airport in New York after another flight attendant in first class served her macadamia nuts in a bag, not on a dish.

The incident in early December last year, which media has dubbed the "nut rage" case, has aggravated public resentment of South Korea's powerful family-run conglomerates, called chaebol, which are seen as dominating the economy and contributing to a widening wealth gap.

Prosecutors said Cho, who has been held in custody by a court since Dec 30, was facing charges of violating aviation security law and obstructing a government investigation. Deputy chief prosecutor Kim Chang Hee told reporters Cho had disrupted the flight and "threatened the plane's safety".

The Airbus A380 on which Cho was travelling had pushed back from its gate but returned for the chief attendant to disembark. It arrived in South Korea 11 minutes late.

The Transport Ministry had concluded that Cho abused flight attendants and that airline officials may have tried to cover up the incident.

Another airline official was detained over allegations that he abetted perjury and obtained information on the ministry's investigation to update Cho.

Public outrage grew when Korean Air initially issued what many members of the public took to be a half-hearted apology that instead appeared to rationalise Cho's conduct in the face of what it said was inadequate performance by the cabin crew.

"The unprecedented case of the plane's return undermined Korean Air's credibility and also damaged national dignity," the Seoul Western District Prosecutors' Office said in a statement.