21st Century Fox and Walt Disney shareholders approved the sale of Fox’s entertainment assets Friday, moving one of the biggest media mergers in history nearer to completion.

The companies' investors gave their blessings to the $71.3 billion transaction in separate votes at the New York Hilton Midtown in Manhattan. When the deal was announced in December, Disney said it would take 12 to 18 months to close -- a timetable the company is sticking with. Upon completion, a new Fox will emerge focused on broadcast TV, sports and the Fox News Channel.

Disney Chief Executive Officer Robert Iger now must turn his attention to the deal's many loose ends -- to consummate the merger and prepare his company for life afterward. Below is a look at some of his remaining challenges:

To win regulatory approval in the U.S., Disney has agreed to divest Fox's 22 regional sports channels. The company already owns ESPN, the biggest sports network. Bidders for the properties, which could fetch as much as $20 billion, may include companies backed by cable billionaire John Malone, private equity and regional broadcasters.

Some analysts also see the possibility that Iger will look to cut a deal with Comcast Corp. over that company's 30 percent interest in Hulu. When the Fox deal closes, Disney will become the majority owner of the video-streaming service.

Although Comcast said last week it won't continue bidding for Fox's assets, the Philadelphia-based cable TV giant has the highest offer on the table for British satellite-TV provider Sky at $34 billion. Disney is acquiring 39 percent of Sky through the deal with Fox and still technically has a bid on the table for the broadcaster.

Some analysts have suggested Iger may cede Sky to Comcast, freeing Disney from the $19 billion or so it would take to purchase the rest of the business.

Disney has pledged to generate $2 billion in cost savings as a result of the merger, which will unite two of the six largest Hollywood studios.

That's created a lot of angst at Fox and Disney, where overlapping marketing, ad sales and distribution departments at their respective film and TV units could lead to hundreds if not thousands of job cuts. Fox had 21,700 employees at year-end, according to data compiled by Bloomberg, while Disney has 199,000.

Some executives are already negotiating their future, with Fox Networks Chairman Peter Rice expected to take a similar role overseeing the combined companies' TV business, with the exception of ESPN. Fox TV studio co-Ceo Dana Walden is expected to lead their TV production business.

Disney has dominated the worldwide box office in recent years, thanks the string of hits from Marvel, Pixar and "Star Wars." Post-Fox, Disney studio chief Alan Horn will have to make choices about which newly acquired franchises to greenlight, including "Avatar," "Planet of the Apes" and "Alien," all of which could also be ripe for expanded merchandise and theme-park attractions.

Fox has produced several movies based on characters licensed from Marvel, including the X-Men and Wolverine pictures and two "Deadpool" movies. Those rights will come back to Disney with the merger.

Disney has received clearance to buy the Fox assets from the Justice Department, but was also awaiting the approval of the Federal Communications Commission.

In addition, the company said in a recent filing it may need consent from regulators in 14 countries and the European Union.