German airline giant Lufthansa on Friday slashed its 2024 profit forecast after a weak second quarter, and warned it would be "challenging" for its flagship carrier to break even.

The group now expects operating profit of 1.4 to 1.8 billion euros ($1.5 to $1.9 billion) for the year, down from a previous estimate of around 2.2 billion euros, it said in a statement.