By Steve Quinn
JUNEAU Alaska (Reuters) - Alaska voters looked on track to narrowly uphold a new law that cuts taxes on oil production and is worth up to $1 billion a year to companies such as ConocoPhillips , BP Plc and Exxon Mobil Corp .
With 80 percent of voting precincts reporting results in Tuesday's primary, those favoring the law held a four-point lead, according to unofficial returns posted by the Alaska Division of Elections.
Upholding the 8-month-old tax reduction ushered in by Governor Sean Parnell means the state would not revert back to the system implemented by his old boss, Sarah Palin, who raised taxes in 2007.
Results will not be certified until Sept. 2, said state elections director Gail Fenumiai, who added that nearly 11,000 absentee ballots needed to be counted over the next 10 days.
Parnell, who claimed his own victory in the state's Republican primary election on Tuesday night, has said his tax rollback will make Alaska more competitive for investment and North Slope oil producers. He called the More Alaska Production Act crucial to the state's long-term future because it would reverse declining output.
Repeal backers got on the ballot last year with a petition featuring 50,000 signatures shortly after Parnell signed Senate Bill 21. They have faced opposition that has raised close to $15 million compared with their several hundred thousand dollars.
Those pushing for the repeal said Parnell's system only put more money in the oil companies' pockets for investment elsewhere while depleting the state's fiscal war chest.
(Reporting by Steve Quinn in Juneau, Alaska; Writing by Eric M. Johnson; Editing by Lisa Von Ahn)