By Gabriel Araujo

SAO PAULO (Reuters) - A deal between Brazilian airline Azul and its lessors to swap more than $500 million in obligations for an equity stake is good news for planemaker Embraer, analysts say, as it reduces concerns about the debt load of a key customer.

Azul had 21 next-generation E2 jets in its fleet at the end of the first half and is awaiting delivery of more this year.

"A stronger Azul means a stronger Embraer," the carrier's chief executive, John Rodgerson, told Reuters on Tuesday after the deal with lessors was announced.

Azul agreed to give them up to 100 million shares of the firm to eliminate obligations of around 3 billion reais ($541.16 million).

The carrier, which competes with LATAM and Gol in Brazil's domestic market, has centered its fleet growth plans on Embraer jets. In August, the firm said it expected to receive 15 to 18 new aircraft by the end of 2025.

Azul has firm orders for 51 E195-E2 jets, according to Embraer.

The carrier's orders represented 13% of Embraer's commercial aircraft backlog in June and 28% of E195-E2 orders, JPMorgan analyst Marcelo Motta said.

"Embraer would have had to provision pre-delivery payments of Azul's order in case the airline filed for Chapter 11, likely generating an impact of $20-30 million to P&L (profit and loss)," he noted.

Shares of Azul and Embraer were among the few to trade higher in Sao Paulo on Wednesday, after notching gains on Tuesday. The benchmark index Bovespa slipped more than 1%.

Rodgerson said Azul had expected another eight jet deliveries this year, but it is facing delays as planemakers grapple with supply chain issues.

"We should get eight more, but they are delayed. I want them before Christmas and they are delivering after Christmas," Rodgerson said.

($1 = 5.5436 reais)

(Reporting by Gabriel Araujo; Editing by Jamie Freed)