SEOUL -- A South Korean heiress known for delaying a Korean Air Lines flight in 2014 because she was angry at the way she was served nuts has accused her younger brother of disobeying their late father’s will to manage the airline’s parent company together.

Heather Cho, a former Korean Air Lines executive whose “nut rage” incident made international headlines, said her younger brother was ignoring the wishes of their father, late chairman Cho Yang-ho, for “harmony” in the family’s management of Korean Air parent Hanjin Group.

Brother Cho Won-tae, who was named chairman of Hanjin Group in April and is also chief executive officer of Korean Air, had been making management decisions without prior consultations, according to a statement issued by Heather Cho’s lawyers on Monday.

“Without real consent and enough discussions among inheritors, Cho Won-tae was appointed to represent Hanjin Group,” it said.

“The late chairman had asked the family to lead Hanjin Group with harmony ... yet chairman Cho Won-tae has been making management decisions not aligned with (the late chairman’s) will, and is still being insincere when it comes to family discussions regarding the management of the group.”

The statement added that Heather “intends to listen to the views of various shareholders and hold consultations with them to actively pursue Hanjin Group’s development in accordance with the late chairman’s will”.

Analysts said the statement raised the possibility that Heather Cho could try to join hands with other investors to raise their stakes in group holding company Hanjin Kal.

Hanjin Kal shares soared 20% on Monday, while the broader Korean market closed flat. Korean Air and budget affiliate Jin Air also rose over 4%.

Cho Won-tae, Heather Cho and younger sister Emily Cho hold 6.46%, 6.43% and 6.42% of Hanjin Kal shares respectively.

“We hope that this incident will not hurt the stability of the company’s management or have a negative impact on the company’s value,” Hanjin Group said in a statement.

Heather Cho and Emily Cho stepped down from their positions at Korean Air in April last year, amid public outrage at their behavior.

Days earlier, police had launched an investigation into Emily Cho after she threw a drink at two business meeting attendees. She apologized for her “foolish behavior” and was later cleared of any charges.

Heather Cho made global headlines in 2014 when she lost her temper over the way she was served nuts in first class and ordered the Korean Air flight to return to its gate at a New York airport.

A year before he died, late chairman Cho Yang-ho apologized for his daughters’ missteps and promised the company would “turn over a new leaf” with stronger management led by the board.