(Reuters) -Fox Corp ( FOXA ) unveiled a $1.5 billion share buyback as streaming platform Tubi's first profitable quarter and strong viewership ratings for its news and NFL broadcasts powered its earnings past expectations.

The shares rose 7% as Thursday's results announcement showed the company's strong digital growth and live programming were offsetting pressure from a soft cable TV market and rising content costs.

Its recently launched subscription service, Fox One, is gaining traction through bundles with ESPN and Verizon, building on momentum from its Amazon Prime Channels tie-up.

Fox's ad revenue rose 6% in the first quarter on 27% growth at Tubi and an 18% increase in viewing time for the free streaming service.

Tubi turning profitable marked a major milestone for the ad-supported streamer Fox bought in 2020, which has become a key growth driver by attracting younger, cord-cutting viewers unwilling to pay for subscriptions. It has carved a niche in the crowded streaming market with content that includes everything from licensed movies and series to original programming.

"It (Tubi) has the most original selection of programming among free streaming services. It is gaining time-spent faster than several of its rivals due to its unique content offering," said Ross Benes, senior analyst at Emarketer.

On the sports side, National Football League programming on Fox averaged nearly 22 million viewers in September - up 12% from last year and marking the network's strongest start to an NFL season ever.

Segment-wise, cable network programming revenue rose 4% to $1.66 billion, with advertising up 7% and distribution up 3%, supported by higher affiliate fees across divisions.

Fox's first-quarter revenue rose 5% to $3.74 billion, compared with the estimates of $3.57 billion, according to data compiled by LSEG.

Adjusted profit attributable to Fox's stockholders was $1.51 per share, compared with the estimates of 1.08 per share.

(Reporting by Kritika Lamba in Bengaluru; Editing by Anil D'Silva and Devika Syamnath)