KUALA LUMPUR, Dec 21 (Reuters) - Malaysia has maintained its January export tax for crude palm oil at 8% and raised its reference price, a circular on the Malaysian Palm Oil Board website showed on Thursday.

The world's second-largest palm oil exporter calculated a reference price of 3,679.50 ringgit ($791.63) per metric ton for January. The December reference price was 3,589.09 ringgit a ton.

The export tax structure starts at 3% for crude palm oil in a 2,250 to 2,400 ringgit-per-ton range. The maximum tax rate is set at 8% when prices exceed 3,450 ringgit a ton.

($1 = 4.6480 ringgit) (Reporting by Danial Azhar; Editing by Kanupriya Kapoor)