American Airlines has increased its offer for a new pilot contract by over $1 billion to align with the preliminary agreement reached last week between competitor United Airlines and its pilots.

The revised offer from American Airlines would bring the total value of the four-year contract to approximately $9 billion, matching United pay rates and including benefits such as backpay, sick time, and life insurance, according to CEO Robert Isom’s message to pilots on Friday.

For years, airlines and pilot unions have been negotiating new contracts. With the prolonged pilot shortage coinciding with the recovery of travel demand, unions have gained more bargaining power. Delta Air Lines pilots, for example, approved a new agreement in March that includes 34% raises over four years.

The voting for the current deal was scheduled to begin for American Airlines pilots on Monday. The new offer includes 21% pay bonuses and pay rates on par with United and Delta, as announced by the Allied Pilots Association, their union, on Friday.

The union’s president, Captain Ed Sicher, stated that the leadership will carefully consider whether the comprehensive proposal from management is suitable for a membership vote.

If the proposed changes are not approved in time for the vote, Isom mentioned that the company will be open to returning to negotiations.

“We are committed to reaching a deal and will resume negotiations if necessary. However, it may not be a quick process,” Isom explained. “Running a complex business means that even small changes to our agreed terms can have a significant impact. Revisiting all these elements would require time.”