Maria Sharapova's racket supplier says it is planning to extend its sponsorship deal despite the five-time Grand Slam champion admitting to failing a doping test.

Head CEO Johan Eliasch says Sharapova has made "a manifest error" by her continued use of meldonium after it became a banned substance this year, but adds there is no "evidence of any intent by Maria of enhancing her performance or trying to gain an unfair advantage."

Eliasch says his brand "is proud to stand behind Maria, now and into the future and we intend to extend her contract. We look forward to working with her and to announcing new sponsorships."

Nike, TAG Heuer and Porsche suspended their commercial ties with Sharapova after she revealed her use of the drug for medical reasons Monday.