Revenue Commissioner Bryan Butcher says the Parnell administration intends to submit legislation to change Alaska's oil tax structure.
   
One element being looked at is production tax credits, which could top $1 billion next fiscal year. The full benefit of that program to the state remains somewhat murky.
   
Gov. Sean Parnell is considering tax changes as a way to boost declining production.
   
Oil is responsible for about 90 percent of Alaska's unrestricted revenue, money that is easier to access and spend.
   
The Revenue Department says unrestricted general fund revenue could be $1.6 billion lower than earlier forecast for fiscal years 2013 and 2014 due to factors including lower-than-expected oil prices. Such revenue is forecast to be between $6- and $7-billion a year for the next nine years, assuming higher oil prices.