Sky says it has completed its purchase of Spark's Lightbox service - and that it plans to merge Lightbox with its own entertainment streaming service, Neon.

Some 130,768 "active" Lightbox subscribers will come under Sky's umbrella as part of the deal (active is defined as using the service in the past 30 days).

But Sky won't say how many paid for Lightbox, and how many got it under Spark's "Lightbox on us" promo by dint of being a Spark broadband customer.

Sky says that, for now, there will be no change to either Lightbox or Neon.

Once the two services are merged, Spark customers who currently belong to Lightbox will be presented with some kind of yet-to-be-defined offer for the combined service.

A spokeswoman for Sky said the Neon-Lightbox merger would happen "towards the middle of the year".

Spark first put Lightbox on the block in March 2019, preferring to focus its firepower on sport - which some would see as a sensible decision as the likes of Netflix, Disney+ and Amazon Prime Video globalise entertainment.

Sky announced on December 19 that it was the buyer, for an undisclosed sum.

Sky's $13.95 per month, no-contract Neon streams movies and TV shows, drawing heavily on Sky's HBO rights. Its Lightbox acquisition comes with rights to a number of Hulu original series, including The Handmaid's Tale.

In October, at its full-year result briefing, Sky said it had 161,000 streaming customers across Sky Sport Now and Neon, but did not offer a breakdown.

Chief executive Martin Stewart did say that streaming customers were now rising faster than satellite customers were falling - allowing Sky to eke out a net gain in total subscribers (which rose 1 per cent to 779,000 for the first time in years.

The bad news: streaming subs pay less than those who use decoders, and average revenue per user per month (Arpu) sunk from $77.73 to $74.84 overall, contributing to another fall in revenue and profit.

NZ Rugby takes a bath

Sky shares closed yesterday at 69c, down 64 per cent over the past 12 months and equalling an all-time low also struck last month. The company's market cap is now just a shade over $300m.

Sky's ongoing fall means NZ Rugby's 5 per cent stake - worth just over $20m when the stock was handed over as part of the new Sanzaar deal mid-October - is now worth just over $15m. (Some analysts think Sky is over-sold and see it rebounding. But, for now at least, it's looking like the NZR should have taken more of its payment in cold, hard cash.)

Spark closed at $4.66. The stock is up 16 per cent over the past year, and the telco and budding sports broadcaster now has a market cap of $8.6 billion.