Its $4.83 billion deal to acquire Yahoo Inc. announced Monday will allow the nation’s biggest wireless carrier to become a meaningful player in the digital media industry, which could be as large as $180 billion by 2020, CEO Lowell McAdam said.

“Verizon intends to be a significant player in this space,” Mr. McAdam said on a conference call.

The carrier is hoping that pairing Yahoo’s one billion monthly active users with its own 113 million subscribers will create a new growing revenue stream at a time when its core business is slowing. On Tuesday, Verizon reported slowing retail postpaid subscribers and a 5.3% revenue decline for the quarter ended June 30. It was the first quarterly drop in revenue since 2010.

“There’s been a lot made of are we going to challenge Google and Facebook in this process,” Mr. McAdam said. “We’re a small player today relative to them. All we need to do is take more than our fair share of the growth of the market and this will be a success for us.”