In a surprise announcement late Friday (17 November), Sprint said COO of Technology Gunther Ottendorfer (pictured, right) is leaving the company at the end of the year.

Sprint indicated Ottendorfer is heading for the door “to join his family in Austria and pursue other opportunities”. In his absence, CTO John Saw will lead Sprint’s network, technology and product development groups. Saw will continue to report to Sprint CEO Marcelo Claure.

A Sprint representative said in his more than two years at Sprint, Ottendorfer “helped drive new technology innovations and steadily improve the performance of our network. We thank him for his leadership and dedication. He will be missed and we wish him all the best in his next endeavour.”

Ottendorfer addressed his departure in a Twitter post:

During his tenure at Sprint, Ottendorfer was known for sporting bright yellow tennis shoes and served as one of the operator’s primary public faces at industry events. Ottendorfer joined Sprint in 2015 after serving for a year and a half as CTO of Telekom Austria Group. Prior to the Sprint move, Ottendorfer also held positions as COO of T-Mobile Austria and technology director for T-Mobile Europe.

Ottendorfer’s exit comes on the heels of a breakdown in merger negotiations between Sprint and fellow US operator T-Mobile. The pair tried to come to terms on a deal which would have created a third massive operator in the US market, but could not agree on which parent company would retain control of the merged entity.