"I know many New Zealanders will join us in expressing their sorrow at his passing."
NZRU Chief Executive Steve Tew added: "Rugby has lost a great friend. We will all miss his integrity, dogged determination and incredible sense of justice."
Hobbs' son Michael, who plays for the Blues, returned from South Africa last week to be at his father's bedside in the intensive care ward at Wellington Hospital.
All Black Cory Jane tweeted: "RIP Jock Hobbs.. A Great man and legend for all he did for NZ rugby..''.
Prime Minister John Key said he was "incredibly sad" after hearing the news.
"I have known Jock for a long time and have enjoyed his company on many an occasion. We have talked and laughed and discussed the country's political and sporting problems. I will miss him very much.
"Jock was the man who convinced Dublin that New Zealand should host last year's Rugby World Cup. This was possibly his finest hour. Winning the trophy was certainly one of New Zealand's finest hours," said Mr Key.
"Jock was a man whose determination drove him to many successes in his life. It was that determination that saw him wage war against his illness for a prolonged period.
The Labour party also expressed its sympathy to Hobbs' family and friends.
"Jock Hobbs was a tremendous Kiwi who dedicated his life to our national sport and was a driving force behind New Zealand's successful bid for the 2011 Rugby World Cup. We will always be grateful for his contribution to our country.
"He was an inspiration to all Kiwis not only for his amazing achievements as a top sportsman and administrator but also for the courage he showed while battling his illness.''
Sanzar tweeted: Sanzar's thoughts are with the Hobbs family, as former All Blacks captain and NZRU chairman Jock Hobbs has passed...''.
The man who saved rugby
His passing came six years after he was first diagnosed with leukaemia in 2006.
Unexpected complications arose soon after he completed his chemotherapy treatment in May 2010, and eight months later Hobbs was diagnosed with non-Hodgkin's lymphoma, which required a more aggressive treatment regime.
That prompted him to resign as NZRU chairman, a position he had held since 2002, as well as chairman of Rugby New Zealand 2011 Ltd, the organisation entrusted with organising the World Cup tournament here.
Hobbs played a considerable role in New Zealand winning the right to host the 2011 World Cup and he attended a number of games at the tournament despite his ailing health. He even presented both Richie McCaw and Mils Muliaina with their silver caps for playing 100 tests in simple but emotional ceremonies and also spoke to the team on the eve of the World Cup final against France.
A lawyer by profession, Hobbs played 21 tests for the All Blacks as an openside flanker between 1983 and 1986, four of them as captain, before the Canterbury loose forward's career ended prematurely at the age of 26 after he had suffered repeated cases of concussion.
Hobbs then devoted his energies to a growing family and his legal career before emerging as arguably the most important rugby administrator of his generation.
He was a fresh faced NZRU councillor in 1995 when he fronted as a central, unifying figure to defuse a potentially explosive rift between the players and the NZRU when rugby went professional.
Hobbs was lauded as "the man who saved rugby'' after persuading All Blacks poised to join a breakaway professional circus to return to the NZRU fold.
The defection of New Zealand's top players to the Kerry Packer-backed World Rugby Corporation was considered a done deal until Hobbs, still a fledgling administrator, worked around the clock for six weeks to secure the players' signatures for the NZRU.
As well, the delicate negotiations were complicated by the need to finance the new professional game, which was achieved through a 10-year funding stream from Rupert Murdoch's News Ltd, which financed the Super competition between franchise teams from New Zealand, Australia and South Africa.
For all of this Hobbs was unceremoniously dumped from the NZRU council the following year when a revamp saw the number of seats trimmed to nine, and he did not figure at the head table again until his services were sought out following the debacle surrounding New Zealand's loss of the sub-hosting rights for the 2003 World Cup tournament.
He was installed as board chairman in 2002 to pick up the pieces and rebuild the organisation's reputation, something he achieved to such a degree that he was able to plot New Zealand's successful bid to host the 2011 World Cup - which arguably will be his lasting legacy.
Hobbs is survived by his wife Nicky, a sister of former All Blacks fullback and Wallabies coach Robbie Deans, and four children.
