TOKYO — Japan’s five Tokyo-based commercial TV networks will jointly launch a service to stream their new shows on the Internet, starting in October.

Called TVer, the service will offer the shows, including popular variety and drama programs, free of charge with commercials generating revenue. Each network will supply about ten shows weekly and each show will be streamed for about one week.

The service will be operated by Present Cast, a joint venture launched by the five networks and four ad agencies in 2006 to provide an online portal for video content, dubbed Dogatch.

The aim is to both attract younger viewers, who have been deserting terrestrial TV, and to thwart illicit online uploads of copyrighted material.

At least two other video platforms will launch in Japan this fall: Netflix and Bonobo, backed by 29 content owners and representatives known as Japan Contents Group.