The two office-holders represent the NZRU and the wider country at important functions and events, both locally and overseas.
They are entitled to attend NZRU Board meetings, although they are not considered members and do not vote on board matters.
Osborne will take over the president role in 2019 - which is Rugby World Cup year.
He will become the first Whanganui-born president since Ernie Bevege in 1961.
Now living in Tauranga, William Michael 'Bill' Osborne played 48 matches for the All Blacks, including 16 tests, from 1975-82, being regarded as one of the world's best second-fives and centres.
He went on to earn an Executive MBA (with distinction) from Waikato University in 1995, and would work in significant roles with 15 companies around the country, including being chief executive of Quotable Value NZ and the co-founder of 2 Degrees Mobile.
Previous Whanganui presidents of the NZRU were Walter Epsom (1900), George Spriggens (1917), Dr George Adams (1930), Geoffrey Pownall (1932) and Bevege.