The two companies, along with Germany’s Siemens, said they were resuming access to their electronic design automation (EDA) tools for Chinese customers.
Synopsys and Cadence rose 5.9% and 5.4% respectively in the U.S, and Siemens gained 1.3% in Frankfurt trading.
Together, the three firms control more than 70% of China’s EDA market, according to an April report from state-run Xinhua News Agency.
EDA software is critical for designing semiconductors used in smartphones, cars and computing devices.
The US Commerce Department also moved to withdraw a licensing requirement on ethane exports to China imposed earlier this year.
Both measures were part of a series of tit-for-tat trade restrictions initiated under President Donald Trump’s administration following China’s suspension of rare earth exports in April.
