"Obviously we're incredibly happy to get Luol signed," general manager John Paxson said at a news conference Thursday announcing the six-year contract. "It's the type of thing that gives him security and gives us the direction we're going to go here in the future."
The team did not release financial details of the deal, first announced Wednesday, but several news outlets have reported it is worth $71 million in guaranteed money and up to $80 million.
The 23-year-old Deng, named a captain last season, said he welcomes any added pressure.
"This brings a lot of responsibilities," he said. "Those are responsibilities I'm looking forward to, on and off the court. I take basketball very seriously and I look forward to putting the team on my shoulders."
The Bulls had a major setback last season, dropping from the playoffs to the draft lottery. Coach Scott Skiles was fired in midseason and their highest-paid player, Ben Wallace, was shipped to Cleveland.
Deng and guard Ben Gordon both turned down extensions before the season and some blamed the team's downward spiral on the uncertainty over the players' futures.
But this summer has looked brighter. The Bulls improbably landed the No. 1 pick in the draft and took local star Derrick Rose, a fast-paced guard out of Memphis. And after some initial stumbling, they got a new, young coach in former NBA guard Vinny Del Negro.
The first-time coach has met with Deng to discuss his potential.
"Luol is not only a terrific player, but he's a great person," Del Negro said. "I think he has room for improvement and is going to be a big cornerstone of what we do and what this franchise is going to do for a long time."
Although Deng wound up getting more money, Gordon's future with the team looks murkier than ever. If they can't work out an extension, Gordon could sign a one-year tender offer and become an unrestricted free agent after next season. Or the Bulls could ship him out in a sign-and-trade deal.
Deng had said he wanted a deal before he went to England in August to help the national team qualify for next year's European basketball championships.
"Getting this done and getting him settled was obviously a priority for us," Paxson said. "We got it done before he headed off to Great Britain to play. It's just a good day for the Bulls."
Originally drafted by the Phoenix Suns in the first round in 2004, the Bulls acquired Deng's rights in a draft-night deal.
Deng averaged 17.0 points and 6.4 rebounds in his fourth season with the Bulls, playing just 63 games as the team finished a disappointing 33-49.
Skiles was fired on Christmas Eve and his replacement, assistant Jim Boylan, never gained a foothold with a seemingly distracted squad.
"Last year was tough," Deng said. "I'm excited for the season and I know all my teammates are too. What happened last season was something we don't want to go through again.
"There are guys already in here working hard and trying to turn it around" he said.