The broadcasters had previously expected to close the deal this year, but this is likely to be delayed should UK culture secretary Karen Bradley proceed with plans to refer the transaction to the Competition and Markets Authority (CMA), according to a trading statement from 21st Century Fox.
The deal "has been cleared on public interest and plurality grounds in all of the markets in which Sky operates except the UK, including Austria, Germany, Italy and the Republic of Ireland", according to the statement. It must now be approved by the UK government and by Sky shareholders unaffiliated with 21st Century Fox.
Earlier this week, the government's Department for Digital, Culture, Media and Sport (DCMS) wrote to telecoms market regulator Ofcom to seek "further clarification" about submissions it had received following Bradley's announcement that she was 'minded to' refer the deal to the CMA. Her announcement was based on media plurality concerns flagged by Ofcom as part of a public interest assessment.
"After assessing the large number of representations made in relation to [Bradley's] referral decision, a number of these raise new evidence and/or comment on the Ofcom assessment," DCMS said in a statement.
"Any referral decision by the secretary of state must be taken on the basis of a valid assessment of all the relevant evidence. For this reason the DCMS has asked Ofcom to advise on a number of points arising from these representations. The department has asked that the advice is provided as soon as possible and no later than 25 August 2017," it said.
Fox already owns a 39% stake in Sky.
Bradley asked Ofcom to review the planned deal in March, and to make a recommendation on whether it should be allowed to go ahead on public interest grounds. In its report, it warned that a merger of Sky and Fox would have "material influence over news providers with a significant presence on television, radio, printed newspapers and online", given the Murdoch family's ownership of The Sun and The Times newspapers.
Ofcom separately concluded that it had no "reasonable basis" to conclude that Sky would no longer be a fit and proper holder of broadcast licences if owned and controlled by Fox.