American Airlines (AA, Dallas/Fort Worth) has announced it is ending its codesharing agreements with Qatar Airways (QR, Doha Hamad International) and Etihad Airways (EY, Abu Dhabi International).

In a statement, the carrier said it had notified both the Gulf-based carriers of its intention to cancel existing agreements on June 29. Codeshared flights will, however, run through to Mach 24, 2018.

American Airlines said it had based its decision on its ongoing dispute with the Middle Eastern carriers regarding their alleged access to state-backed subsidies which, it claims, has distorted the market. In May this year, United Airlines discontinued ticketing and baggage interline agreements with Qatar Airways, Emirates, flydubai, Saudia, and Royal Jordanian on similar grounds.

"Given the extremely strong public stance that American has taken on the ME3 issue, we have reached the conclusion that the codesharing relationships between American and these carriers no longer make sense for us,” American Airlines said adding that interline and cargo agreements, frequent-flyer program cooperation, and lounge access would not be affected.

American's announcement comes at a time when Qatar Airways is preparing to make an unwanted bid to acquire up to 10% of its shares.