BEIJING—A Chinese court sentenced three people to prison terms for collaborating to steal information from a key supplier regarding Apple Inc.'s iPad 2 several months before its release, the latest outcome from leaks about products made by the technology giant.

The Shenzhen Bao'an People's Court, in announcing its decision, said the head of a Chinese electronics-accessories manufacturer allegedly paid a former employee and a then-active employee of Taiwan's Hon Hai Precision Industry Co. for information about the iPad 2 in...