Current TV, the network co-founded by former U.S. Vice President Al Gore, was sold for about $500 million to Al Jazeera, the Qatar-based cable-news channel, according to two people with knowledge of the deal.

The proceeds represent an eightfold increase from the $60 million Gore and his partners paid for its predecessor in 2004, said one of the people, who asked not to be named because the terms are private. Gore, chairman, and Joel Hyatt, a co-founder and chief executive officer, announced the sale Wednesday in a statement, without providing financial terms.