LOS ANGELES (Variety.com) - Comcast -- finally -- is allowing its customers access to the HBO Go and Showtime Anytime online-video services on Roku's TV-connected streaming devices.

The nation's largest cable operator, however, still does not have a deal to offer the Starz Play authenticated service on Roku, among other TV Everywhere services.

Neither Comcast nor Roku have ever explained why the MSO's customers could not access HBO's and Showtime's authenticated-video services on the Roku devices.Comcast has offered subscribers access to both HBO Go and Showtime Anytime apps on several other platforms, including Apple TV, Microsoft Xbox One and Google's Chromecast.

Matt Strauss, senior VP and g.m. of video services for Comcast Cable, announced the agreement with Roku in a blog post Tuesday.

"With the addition of these channels on Roku, we now authenticate more than 90 network apps on up to 17 different devices," Strauss said. "And those numbers will continue to grow as new technologies and platforms emerge."