Employees accepting the early-exit program will receive a lump sum payment, a spokesperson for the airline said.
A formula to have the maximum payout was not released.
United, which is a unit of the parent company United Continental Holdings hopes for up to 2,100 takers of its buyout offer. There are over 23,000 attendants working for United, said the airline.
Attendants returning from furlough also will help in some airports that had been thinly staffed, said the spokesperson.
The airline representative said the cost was less to have a less experienced flight attendant than one that is more experienced.
The Association of Flight Attendants took part in buyout discussions and issued the news jointly with the airline on Monday.
United maintains a separate collective bargaining agreement for its two sets of flight attendants. One is made up of those who were originally working for United, while the other is those who had been with Continental prior to the merger of the two airlines.
The buyout offer is for the members of both groups in order of seniority.
United, which is Chicago-based, has generally been underperforming in comparison to rival airlines based in the U.S. since it completed merging with Continental Airlines 4 years ago.
The airline had a $609 million loss during the first quarter, which marked the only air carrier in the U.S. to post a loss for those three months and then posted $789 million in net income for the second three months of 2014.
United shares have increased 31% in 2014, compared to a rise of 43% for Delta, 47% for American Airlines and 80% for Southwest Airlines.