Taiwan has changed the names of state-owned enterprises, dropping "China" from their titles.
As of Tuesday, the Chungwha Post Company will be known as the Taiwan Post Company, and the Chinese Petroleum Corporation will be referred to as the CPC Corporation.
The names of Taiwan's shipping companies will also drop all references to China.
The U.S. opposes the name changes, saying it does not favor Taiwan taking steps that would change its status unilaterally or move toward independence.
Taiwan officials say the changes are necessary to keep state-run companies from being confused with those in China.
Taiwan and China split at the end of a civil war in 1949. Beijing claims sovereignty over the self-governing island and has threatened to use force if Taiwan makes any formal moves toward independence.