Sky owner Comcast is suing Warner Bros. Discovery alleging a breach of its programming supply contract.

In 2011 Sky entered an exclusive agreement giving it broadcast rights to HBO's library of existing and new comment, primarily for the freshly-launched Sky Atlantic channel.

Since then the parties have extended the arrangement multiple times, although when the current deal ends at the end of 2025, Warner Bros. intends to not renew the deal and instead launch its own premium 'Max' service, which is already widely available in other parts of the world.

However, with that deadline now fast approaching, Comcast has launched a lawsuit alleging that Warner Bros. has failed to fulfil its contract by not providing a sufficient number of shows.

"Warner has repeatedly failed to offer Sky the annually required minimum number of contractually qualifying series for its consideration," the lawsuit says, according to Deadline.

"Specifically, Warner was obligated to present Sky with at least four shows per year across 2021, 2022, and 2023 but undisputedly fell far short of that mark, in certain years offering barely a single qualifying series while also withholding critical, contractually required information necessary for Sky to evaluate any potential options that it did receive."

The lawsuit also alleges that Warner Bros. did not offer Sky the opportunity to co-produce the new Harry Potter TV franchise which is due to debut in 2026 or 2027.

A WBD spokesperson said in response: "The HBO and Max licensing agreements expire at the end of 2025, and this lawsuit is a baseless attempt by Sky and Comcast to try and gain leverage in its negotiations for our programming beyond that date.

"We know HBO-branded shows are critical to Sky, as evidenced by their desire for over a year to find a way to renew our agreements, and this lawsuit makes it clear that Sky is deeply concerned about the viability of its business were it to lose our award-winning content.

"WBD will vigorously defend itself from this unfounded lawsuit as we move forward undeterred with plans to launch Max, including the new HBO Harry Potter series, in the UK and other European markets in 2026."

A Sky spokesperson said: "We continue to work constructively with Warner Brothers Discovery and have a separate agreement in place that will ensure Sky customers continue to enjoy HBO shows, including new seasons, such as House of the Dragon, The Last of Us, The White Lotus and Euphoria, along with exciting new releases such as Dune: Prophecy, and many more for years to come."

HBO content continues to pull in some of Sky's largest audiences across its channel portfolio, with the recent season of House of the Dragon averaging around 3 million total viewers.