Roger Dubuis, a master watchmaker and the co-founder of the Swiss brand that bore his name, died on Oct. 14. He was 79.

The company announced his death in an email statement but did not disclose its cause.

“The death of our founder is a heavy loss for the entire watchmaking community,” the Roger Dubuis employees wrote in a separate joint statement. “His unique mastery of haute horlogerie, his avant-garde vision and his human values will remain deeply engraved in our hearts.”

Jean-Marc Pontroué, the company’s chief executive since 2011, said, “Roger was a charming and moving person, and an artist of technique and complications. His passing, after some 22 years with the company, is for us a moment of sadness and emotion.”

Mr. Dubuis retired from the company in 2005 but, at Mr. Pontroué’s urging, returned as a brand ambassador in 2011. “As an ambassador, Roger was there at product launches to meet with clients and retailers,” Mr. Pontroué said. “It is rare for any brand to have its founder present.”