In what Walt Disney Co. president and chief executive officer Robert Iger called "a great opportunity at the right time," Disney is buying Marvel Entertainment Inc. in a $4 billion cash-and-stock deal, putting Spider-Man under the same umbrella as Mickey Mouse.

Under the terms of the deal, Marvel shareholders will receive $30 cash and 0.745 shares of Disney stock (NYSE: DIS) for every share of Marvel stock (NYSE: MVL) owned.

At closing, the amount of cash and stock might be adjusted such that the total value of the Disney stock issued is not less than 40 percent of the total merger consideration, based on its trading value at that time.

Both boards of directors have approved the deal, which is slated to close by the end of the year.

On a conference call with investors, Disney said that the deal will be accretive to earnings in two years.

Disney also said that the deal will result in the issuing of 59 million new shares, but Disney would enter a buyback program to repurchase the same amount of shares during the next 12 months, as to not dilute stockholder value.

The deal gives Disney ownership of Marvel's portfolio of more than 5,000 characters, which include such iconic characters such as Spider-Man, The Incredible Hulk, the Fantastic Four and the X-Men, many of which have been turned into successful movie franchises in recent years.