YouTube has started to experiment with its own-brand live video-streaming technology.
Over two days the site is planning a trial in which four partners will get the chance to air live programmes.
YouTube has done one-off live events in the past, but the trial marks a test of underlying technology that will be used when the service is launched.
The live programming system is likely to be only open to media partners rather than individual web users.
YouTube partners Howcast, Rocketboom, Next New Networks, and Young Hollywood will take part in the test that runs from 13-14 September.
Rocketboom said it would be showing an hour-long variety show that resembles the programmes seen on TV.
Dan Cryan, head of broadband at Screen Digest, said changing tastes meant YouTube was unlikely to become a broadcaster like existing TV channels.
"For much of traditional TV programming there's a move to consume it on-demand and consumers are increasingly beginning to expect that," he told BBC News.
"There are certain things that work better live, sports being the obvious example, but other forms of event TV work too," he added. YouTube was much more likely to set up a system that could handle such live TV events and deliver an audience to them.
Live streamed video seen on YouTube before now has included President Obama's first State of the Union address, Indian Premier League cricket matches and a U2 concert. Its political channel CitizenTube has also occasionally used live streaming.
However, all these have been isolated incidents and the technology being tested over the two day trial will help its partners stream a continuous service. It is reported to have said that it will not be archiving any live programmes.
The trial is billed as an "alpha" or early test of the technology YouTube is developing to underpin the live programming.
Before now, YouTube relied on other content delivery networks such as Akamai to get live video to viewers.
YouTube has given no official date for when development on its live-streaming technology will be finished or when the service will be offered to all its partners.
By moving into live streaming, YouTube will bump up against a whole series of new rivals including Ustream, Justin.tv and Livestream.