KB Holding GmbH, Thiele family's investment vehicle, sold 33 million of its 60 million shares, the statement said, at a placement price of 9.80 euros per share.
The placement price represented about 10 percent discount to Thursday's closing price of 10.8680 euros and made the sale worth 323.4 million euros ($395.42 million).
Heinz Hermann Thiele, majority owner of German braking systems maker Knorr-Bremse, died in February at the age of 79.
Thiele had acquired a major stake in Lufthansa and became a highly visible public figure last year when portrayed as the main obstacle to the state bailout the airline needed to survive the coronavirus crisis.
Morgan Stanley Europe SE was acting as bookrunner for the sale.
Bloomberg News reported the sale earlier on Thursday.
Earlier this month Reuters reported that the airline was working with Deutsche Bank and Bank of America to sound out investors about a capital increase worth roughly 3 billion euros, possibly as soon as June, to repay a government bailout in 2020.
($1 = 0.8179 euros)
(Reporting by Arno Schuetze and Alexander Hübner; Writing by Radhika Anilkumar; Editing by Richard Chang and Grant McCool)
