Investing.com -- United Airlines flight attendants approved a new five-year labor contract on Tuesday, securing 31% average raises to base pay by August and marking the final major carrier with unionized flight crews to reach a post-pandemic labor deal.

The agreement, which covers approximately 30,000 flight attendants, received 82% approval with close to 90% of crew members voting. This represents the group's first pay increases in nearly six years.

"The contract will immediately change the lives of United Flight Attendants, especially our thousands of new hires who have been hired since the pandemic," said Ken Diaz, president of the United chapter of the Association of Flight Attendants.

The company and union reached a preliminary agreement in March after crews rejected a previous contract proposal last year.

Under the new terms, flight attendants will receive boarding pay for time when the aircraft door is open and passengers are boarding. Airlines had traditionally started flight attendants' pay clock only after the boarding door closed.

The contract includes a roughly 7% to 8% increase in total compensation and $741 million in back pay. Additional provisions include restrictions on red-eye flights and "sit pay" during operational disruptions lasting more than 2.5 hours.