MIAMI — American Airlines is shaking up its senior management team for the third time in less than a year via the departure of yet another senior executive for rival United Airlines.

The headline, revealed in a letter to employees from American president Robert Isom, is the departure of Andrew Nocella, American’s Senior Vice President – Network Planning, Alliances & Sales, who is resigning to step into a leadership role at United.

Nocella follows in the footsteps of longtime American and pre-merger US Airways President Scott Kirby, who left American for United last August to step into an analogous role at the Chicago-based legacy carrier. Kirby and Nocella are joined at United by Patrick Quayle, currently the VP of Network Planning (he was previously the managing director of American’s international network).

Nocella had worked with American and pre-merger US Airways across a variety of functions (including chief marketing officer). The immediate response to Andrew’s departure is not to backfill the role but rather to spread his team of direct reports over to other executives. Alison Taylor, American’s SVP of Global Sales will shift over to report to SVP of Marketing and Loyalty Kurt Stache.

Also from Nocella’s team Vasu Raja (VP – Network & Schedule Planning) and Joe Mohan (VP – Alliances & Partnerships) will begin reporting directly to Isom. It is unclear whether Nocella’s responsibilities will be re-distributed amongst other senior executives, or whether a direct replacement will eventually be hired.

You can read the full letter from Isom below.

Dear Team,

February 15, 2017

We are only halfway through February and it feels like we have accomplished a year’s worth of work (again this year!). Basic economy is set to go to market soon. And, the operation is running on all cylinders as evidenced by our exceptional D0 performance and three consecutive 100% completion factor days last week. By all accounts, the Annual Leadership Conferences were a hit. I know that you will do your best to take care of our frontline team in 2017 – making sure they have the tools, training and support that they deserve.

No doubt, we have a lot going on right now. And, with that also come changes to our leadership team. You already know about some of the recently announced retirements – like Art Torno, Hector Adler and Paul Morell – that have opened up opportunities for Jim Butler, Jill Surdek and Kevin Brickner. We have another change to share with you today. Andrew Nocella has informed me that he is resigning from his position of Senior Vice President – Network Planning, Alliances & Sales and has accepted a leadership role at United.

Andrew has been a valuable member of our team for more than 20 years and we owe him a debt of gratitude for shaping the American Airlines network that we fly today. On a personal level, I have worked closely with Andrew for the last 10 years. He has been a key advisor and a visionary planner – for our network, fleet and alliances. We will miss him.

And while we don’t like seeing people like Andrew leave, we are really fortunate to have an exceptionally talented group of leaders in place and who already oversee those functions that reported to Andrew. So, for now, we won’t backfill Andrew’s position.

Alison Taylor, our Senior Vice President – Global Sales, will join Kurt Stache’s Marketing & Loyalty team. As most of you know, Alison joined us September 2016 and is leading our sales efforts with great enthusiasm – and great results, I might add. Our sales team has never been in better hands and aligning this organization with Kurt’s team will create increased collaboration between all of our customer loyalty, branding, marketing and sales functions.

Next, Vasu Raja, Vice President – Network & Schedule Planning, and Joe Mohan, Vice President – Alliances & Partnerships, will report directly to me. Vasu has been with us for 13 years and has brought a fresh perspective to network planning since he took over this role last year. Joe joined us just last summer and has made an immediate impact drawing on his experience as the CEO of VivaLatinamerica. Stay tuned in the coming months for news on exciting developments that are well underway in Vasu’s and Joe’s areas of responsibility.

I want to again thank Andrew and wish him well. Of course, please feel free to let him know we all look forward to competing against him in the coming years! And, for all of us, I’m very excited about the team we are developing and the future of American Airlines. In the coming months, I’m sure I’ll be back in touch to talk about how we will further align and organize to take advantage of the opportunities ahead. The progress this team has made is remarkable, and we are fortunate to have Kurt, Alison, Vasu and Joe to continue driving us forward.