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

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

Azul ( 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 ( ERJ ) jets. In August, the firm said it expected to receive 15 to 18 new aircraft by the end of 2025.

Azul ( AZUL ) has firm orders for 51 E195-E2 jets, according to Embraer ( ERJ ).

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

"Embraer ( ERJ ) would have had to provision pre-delivery payments of Azul's ( AZUL ) 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 ( AZUL ) and Embraer ( ERJ ) 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 ( 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)