American Airlines has cancelled 115 flights per day until August 19 due to its fleet of Boeing 737 MAX planes being grounded.
The decision to ground all Boeing 737 MAX flights began last month, following the Ethiopian Airlines crash on March 10 which killed 149 passengers and eight crew members.
The decision taken by American Airlines to suspend MAX flights was previously only scheduled until June 5.
In a statement, American Airlines chairman and CEO Doug Parker, said: "These 115 flights represent approximately 1.5% of American's total flying each day this summer.
"Based upon our ongoing work with the Federal Aviation Administration (FAA) and Boeing, we are highly confident that the MAX will be recertified prior to this time (August 19).
"By extending our cancellations through the summer, we can plan more reliably for the peak travel season and provide confidence to our customers and team members when it comes to their travel plans.
"Once the MAX is recertified, we anticipate bringing our MAX aircraft back on line as spares to supplement our operation as needed during the summer."
Dallas-based Southwest Airlines made a similar move by removing the 737 MAX service with United Airlines also cancelling 737 Max 8 flights until June.