LOS ANGELES — Premium cable network Starz Entertainment will end its deal to provide movies to Netflix, a surprise decision that will deprive the popular online video service of its most valuable source of recently released movies.

Analysts had said that if Starz were to renew its agreement, which expires in February 2012, it could have been worth as much as $300 million to John Malone’s Liberty Media-owned network.

But executives at Starz apparently concluded that they would lose even more money by giving consumers a reason to subscribe to Netflix instead of the cable channel.

“This decision is a result of our strategy to protect the premium nature of our brand by preserving the appropriate pricing and packaging of our exclusive and highly valuable content,” Starz said in a statement Thursday. “With our current studio rights and growing original programming presence, the network is in an excellent position to evaluate new opportunities and expand its overall business.”

Starz, which controls pay-cable rights to movies from Walt Disney Studios and Sony Pictures, signed its current agreement with Netflix in 2008. At that time, online video was watched by only a small number of tech-savvy young people and the estimated $30 million per year the cable network received was seen as new revenue that would have little impact on its traditional television business.

But Netflix now has 25 million subscribers, the majority of whom watch video online through a variety of devices, including Internet-connected TVs, tablets and smartphones. By providing recently released hit movies from Disney and Sony such as “Alice in Wonderland” and “The Karate Kid,” Starz has helped to fuel that growth.

The only other recently released movies Netflix gets for its streaming service come from Paramount Pictures, Lionsgate and Metro-Goldwyn-Mayer via cable channel Epix. HBO, which has offerings from 20th Century Fox, Universal Pictures and Warner Bros., has refused to partner with Netflix.

Starz typically costs about $15 a month for cable and satellite television subscribers, while Netflix streaming costs only $8 a month and doesn’t require a pay television subscription.

The move comes two months after Sony movies disappeared from Netflix because of a provision in its deal with Starz. However, people close to the matter had said at the time that they expected Sony movies to return to Netflix soon. With Starz choosing not to renew with Netflix, that will now be a moot point.

The Starz development came on the same day that Netflix implemented a previously announced, controversial price increase that eliminates hybrid plans and charges a minimum of $8 a month to receive DVDs through the mail and $8 a month for online video.

The latter service is likely to become less valuable in the eyes of consumers with the disappearance of Starz’s movies and original TV series such as “Camelot.”