While the blockbuster deal has already raised concerns about the influence of the Australian-born US tycoon over Britain's media landscape, industry observers are also worried that the controversial reporting style of Murdoch's Fox News channel could be adopted by Britain's Sky News.
Today, Karen Bradley, the Conservative government's minister for culture, media and sport, said she intended to refer the bid to British regulator, the Competition and Markets Authority, due to media plurality concerns.
But CMA could also investigate the deal on grounds of "genuine commitment to broadcasting standards", the minister said.
It was "important", Bradley explained, that "entities which adopt controversial or partisan approaches to news and current affairs in other jurisdictions should, at the same time, have a genuine commitment to broadcasting standards here" in the UK.
"These are matters the CMA may wish to consider in the event of a referral," Bradley said.
Last year, 21st Century Fox bid 11.4 billion pounds (USD 15.1 billion, 12.7 billion euros) for the 61-percent of Sky it does not already own.
The takeover has already been approved by regulators in Austria, Germany, Ireland and Italy as well as the European Union, but not yet in Britain.
Britain media watchdog Ofcom has warned of the "increased influence" the deal would give Murdoch over Britain's media landscape.
Bradley's decision won praise from the main opposition Labour party.
"I think it's the first time a minister in the current government has ever stood in the way of what the Murdochs want, and frankly not before time, so well done," said Labour's cultural affairs spokesman, Tom Watson.
Murdoch had previously failed in 2011 to buy the pay-TV group, then known as BSkyB, owing to a phone-hacking scandal at his now-defunct News of the World tabloid newspaper.
21st Century Fox is one of the world's largest entertainment companies with a vast portfolio of cable, broadcast, film, pay-TV and satellite assets across six continents.
Sky broadcasts a similar offering, including the 24-hour Sky News channel and Premier League football, and also provides internet and telephone services.
In late 2014, Sky changed its name from BSkyB after buying Sky Italia and a majority holding in Sky Deutschland.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)