Vice Media, the digital group which has mounted an aggressive assault on traditional news providers, is in talks to sell a major stake in itself to Time Warner.

Sky News has learnt that the two companies have been holding detailed negotiations about a deal.

One potential structure under discussion would see Time Warner injecting HLN, a news platform owned by its Cable operations, into Vice in return for roughly half the enlarged company.

A deal is expected to value Vice at roughly $2.2bn, about 50% more than last year's sale of a stake in the mini-conglomerate.

Sources said on Monday that talks between Time Warner and Vice were at an advanced stage but that some final details had yet to be agreed.

A deal could still fall apart, however, or assume a radically different structure, they added.

Founded in 1994 as a "punk zine" for music enthusiasts in Montreal, Vice has attracted huge attention from the global media industry with its provocative mix of content and rapid diversification: it now houses an advertising agency, a record label and a television show.

The company has built a significant presence in Shoreditch in London, one of 35 offices it now has around the world.

Among the "news events" for which it has become known was a TV show in which Vice's crew took the US basketball star Dennis Rodman to North Korea.

Shane Smith, the company's Canadian co-founder and chief executive, has repeatedly referred to Vice as "the Time Warner of the street" but has denied any intention of surrendering outright control of the group.

Vice operates some of Youtube's most popular channels and has content partnerships with a broad range of digital media providers, including Facebook and Twitter.

Its digital channels now include The Creators' Project, Motherboard and Noisey, a music discovery platform.

"I want us to be the next MTV, ESPN and CNN rolled into one - and everyone always rolls their eyes," Mr Smith told a newspaper last year.

"The reality is that MTV was bought by Viacom and CNN went to Time Warner. We have set ourselves up to build a global platform but we have maintained control."

Vice's management, led by Mr Smith, are expected to retain operational control of the business as part of a deal with Time Warner.

It was unclear on Monday how Vice's existing minority shareholders, which include WPP, the FTSE-100 marketing services group, would respond to a transaction.

Vice's other investors also include 21st Century Fox, which acquired a 5% stake last year in a deal valuing the company at $1.4bn, and Raine, a New York-based merchant bank.

The increase in Vice's purported value since then underlines the extent to which major media groups are keen to forge an alliance with the company.

The original Vice magazine now accounts for less than 5% of the company's revenues, which reached $175m in 2012, with video content dominating its business model.

A deal with Time Warner would provide Vice with the ability to expand its international operations more quickly.

Mr Smith has signalled his desire for Vice to make a significant impact in fast-growing markets such as China, India and South Korea, where multinational consumer brands are keen to align themselves with youth-focused content platforms.

Time Warner and Vice both declined to comment on their talks.