Earlier, this month the European Commission gace its unconditional approval to the £11.7 billion Twenty-First Century Fox takeover of Sky.
Bradley said: "Given the proximity of this decision to the forthcoming general election and following discussions with the parties, Ofcom, the CMA and the Cabinet Office Propriety and Ethics team", she had extended the deadline until June 20th after the state opening of Parliament.
Ms Bradley announced in March that she was intervening in the deal on the grounds of media plurality and broadcasting standards.
Once their reports are received by Bradley, "my decision-making role in this process would resume", the secretary said in a statement. The new deadline falls 12 days after the snap election.
U.S. entertainment giant 21st Century Fox already has a 39% stake in Sky, the owner of Sky News.
Critics say that the bid raises plurality issues because it will give Fox News owner Murdoch control of Sky, which owns Sky News, operations in Germany and Italy and United Kingdom newspapers including the Sun and Times.
Ofcom chief Sharon White will oversee a probe that will also ponder whether Fox bosses are "fit and proper" owners of the United Kingdom satellite broadcaster. Rupert Murdoch and his son Lachlan Murdoch are both joint chairmen of 21st Century Fox and News Corp, while his other son, James Murdoch, is chief executive of Fox.