Along with Mr Dennis three other senior O&Y executives at Canary Wharf are losing their jobs.
They are Charles B Young, the former Citibank executive who was put in charge of Canary Wharf when O&Y bought it in 1987, Robert John, the finance guru headhunted from County NatWest, and Peter Dale, the head of communications.
Two O&Y executives have been asked to stay on - Gerald Rothman, the property services director, and Bob Spiers, the finance director.
The redundancies are part of a restructuring in which 34 staff are being cut from a total of more than 300 employed at the site.
The administrators revealed last week that they had terminated talks with an investor group put together by Paul Reichmann, the chairman of O&Y, which was hoping to regain control of the pounds 1.4bn project.
In addition the banks that have lent Canary Wharf more than pounds 600m have agreed to put up the equivalent of pounds 180m to fund a commitment made by O&Y to invest in the extension of the underground Jubilee Line to London Docklands.
It was widely believed that the possible lifeline being thrown to the project by its former owners was the reason that Ernst & Young had not made the four former O&Y executives redundant earlier.
Mr Dennis, a former law professor who was Toronto's commissioner for housing before joining O&Y, had a reputation for plain speaking and lack of willingness to tolerate dissent.Reuse content