EDMONTON — Alberta has released a fiscal update that shows the province's estimated surplus has more than doubled to $4.2 billion since last April's budget.

The rapid growth in the projected surplus is mainly the result of higher-than-expected investment returns and income tax revenues. There has also been a significant boost in energy-related revenues.

The surplus dollars are being divided between various savings accounts, including the Heritage Fund and a capital fund that will pay for future building projects.

Spending has also increased roughly $700 million since the budget was released, mostly for building projects, flood assistance and a program to battle forest-munching pine beetles.

Finance Minister Lyle Oberg was supposed to release a new Alberta budget last Thursday, but Premier Ed Stelmach's decision to call an election for March 3 put that on hold until after the vote.