Image copyright AFP Image caption The deal is believed to be the biggest so far in the world this year

US telecoms giant AT&T has announced that it will buy entertainment group Time Warner for nearly $86bn (£70bn).

The deal - one of the biggest this year - still needs approval from regulators.

If the takeover goes through, it would combine AT&T's distribution network with content from the Warner Brothers film studios and the cable TV channels HBO and CNN.

AT&T's chairman described it as "a perfect match" but critics say it concentrates too much media power.

'Complementary strengths'

The deal is likely to be closely scrutinised by US antitrust regulators. AT&T is already the third largest cable TV provider in the US.

Randall Stephenson, who is both chairman and chief executive of AT&T, said he did not anticipate any regulatory obstacles, saying any concerns could be overcome if concessions were made.

"This is a perfect match of two companies with complementary strengths who can bring a fresh approach to how the media and communications industry works for customers, content creators, distributors and advertisers," he said.

Analysis: Joe Lynam, BBC correspondent

AT&T has the means by which millions of Americans consume their entertainment. It owns the platform - be that cable or broadband - which enables people to watch their favourite shows. But it does not - until now- own the shows or the "content" which households want to watch, be that Game of Thrones, CNN or live NBA basketball.

Buying Time Warner, which we should not confuse with Time Warner Cable, allows AT&T to become a full service media provider and one of the more important companies in the world.

It allows a newly-merged entity to steal a march on the likes of Verizon or Comcast in a very competitive US market.

But the deal may never happen. It could be deemed anti-competitive by regulators because AT&T already owns mobile phone, broadband and cable TV networks, and allowing it to control the shows as well might deprive consumers of choice.

An AT&T statement said that aim of the deal was to give customers "unmatched choice, quality, value and experiences that will define the future of media and communications" and the new company would "lead the next wave of innovation in converging media and communications industry".

Republican presidential candidate Donald Trump has said if he is elected, he will block the deal.

"It's too much concentration of power in the hands of too few," he said on Saturday, before the deal was confirmed.

Image copyright Helen Sloan/HBO Image caption Revenue from HBO, which shows Game of Thrones, contributes about 18% of Time Warner's total revenue

AT&T will pay $107.50 for each Time Warner share, in a combination of cash and stock, worth $85.4bn overall, according to a statement.

AT&T said it expected the deal to be completed by the end of 2017.

Other media company shares, including Discovery, AMC, Netflix and CBS, recently rose as investors speculated that a deal could spark a fresh wave of takeovers and mergers among media and technology companies.

AT&T, which has a market value of about $238bn, has already made moves to turn itself into a media powerhouse, buying satellite TV provider DirecTV last year for $48.5bn.

Time Warner chief executive Jeff Bewkes has, however, resisted selling in the past. The company rejected an $80bn offer from Twenty-First Century Fox Inc in 2014.

The deal gives AT&T access to a major producer of content as it seeks to diversify away from its core telecoms business. Rival Verizon is currently in negotiations to buy Yahoo and has already bought AOL, owner of Huffington Post.

Some analysts, however, question whether AT&T needs to mount a complete takeover of Time Warner.