The companies gave no details on the scope or nature of the potential cooperation but said in a joint statement that they "are open to deeper collaboration in the future on innovative new technologies".
"By working together on agreements such as this, tech companies can focus on building better products and services for their users," Google's head of patents, Mike Lee, was quoted saying.
Sam Xu, head of intellectual property at Tencent, added that the patent agreement would "advance the collaboration between two leading technology companies".
But any cooperation between the US search giant and China's all-conquering tech leader -- the world's second- and fifth-largest companies by market value, according to Bloomberg News -- is bound to generate buzz in the IT world.
More From This Section
Google effectively withdrew its search engine from China's heavily controlled internet landscape in 2010 in a row over censorship and cyber-attacks, and many of its services remain blocked.
But there have been hints of a thaw in relations.
The agreement with Tencent would apply to a broad range of products, the companies said, without giving any specifics.
Tencent operates China's ubiquitous WeChat messaging platform and is the country's leader in social media and gaming.
It is pushing to build up its entertainment and gaming businesses and has signalled plans to buy studios, expand into content creation and diversify overseas.