American Airlines Group Inc. said changes it offered in a pending contract agreement with pilots would increase the value to more than $9 billion over four years, matching terms of a competitor’s more-lucrative offer.

The proposal adds more than $1 billion to the tentative agreement between the carrier and the Allied Pilots Association, including a “significant” increase in compensation, a ratification bonus and increased life insurance, Chief Executive Robert Isom told pilots in a video Friday. It matches terms of a pending deal at United Airlines Holdings Inc. that’s valued at $10 billion over the same period.

American and the union are scrambling to agree on new terms in time for a vote that’s set to start July 24. Failure would likely mean a delay in voting or ditching the entire agreement and restarting talks.

“We run a complex business and any changes to what we agreed to — even small ones — may have a profound impact,” Isom said. “Reconsideration of all of these items would take time.”

A union spokesman couldn’t immediately be reached for comment. The two sides committed earlier this week to negotiate “around the clock” to reach revised terms.