Sportswear giant Nike suspended its sponsorship, saying in a statement that it was "saddened and surprised by the news." Swiss watch brand TAG Heuer says its deal with the Russian will not be renewed.
TAG Heuer said in a statement that its previous contract with Sharapova had expired at the end of 2015 and it has pulled out of negotiations on a new agreement.
Sharapova, a five-time major winner, on Monday said she failed a test at the Australian Open in January for the banned substance meldonium, a heart medication commonly sold in Eastern Europe. Meldonium was added to the banned list on Jan. 1.