DENVER — Colorado has become the third state to ask the U.S. Drug Enforcement Administration to reclassify marijuana in way that allows doctors to prescribe it as a medical treatment.

The head of Colorado’s Department of Revenue, which oversees the state’s booming medical marijuana business, made the request in a letter sent Dec. 22. It wasn’t released to the public until Wednesday because of the Christmas holiday.

The letter says the discrepancy between state law and federal drug law, which does not permit medicinal uses of marijuana, is problematic.

Last month, the governors of Washington and Rhode Island also asked that the government list marijuana as a Schedule 2 drug, like morphine and oxycodone.

Copyright 2011 The Associated Press. All rights reserved.