* Projects C$4.7 bln deficit for 2009-10, its largest ever

* Revenue pegged at C$31.7 bln, expenditures C$36.4 bln

* Nonrenewable resource revenue seen halved

* No surplus projected until 2012-13 (Adds minister comments, details, background)

By Jeffrey Jones

CALGARY, Alberta, April 7 (Reuters) - Alberta forecast a C$4.7 billion ($3.8 billion) deficit for 2009-2010 on Tuesday -- its largest ever -- as the oil boom that had sustained Canada's top energy-producing province turned to bust.

Alberta, which delivered 14 straight surpluses as its oil industry pumped out cash, may not be back in the black for four years as it looks to shovel C$23.2 billion into infrastructure like roads, schools, housing and health facilities as well as environmental initiatives, the government said.

The combined budget shortfalls could balloon to as much as C$10.3 billion. They will be funded out of Alberta's newly expanded C$17 billion "sustainability fund," made up of savings from previous surpluses and money that was set aside for capital projects and carbon capture and storage.

The red ink is blamed on projected revenues from energy being slashed by more than half from last year as weak commodity prices and the credit crunch forced the industry to rein in spending. Alberta is one of the largest suppliers of oil and gas to the United States.