By Keith Coffman

DENVER, March 10 (Reuters) - Sales of recreational marijuana products in Colorado added more than $2.1 million to state coffers in tax receipts and other fees in the first month retail sales of the drug were allowed, state figures showed on Monday.

The figures, which the Colorado Department of Revenue said were in line with expectations, add to just over $1.4 million collected in taxes and fees on medical marijuana in the state in the same month.

The figures for recreational marijuana include revenues from a 2.9 percent sales tax, a special 10 percent tax on retail pot sales and a 15 percent excise tax imposed on growers, as well as licensing fees, the department said in a statement.

The numbers indicate the state's recreational pot stores did about $14 million in gross sales for the month.

"We expect clear patterns will emerge by April and plan to incorporate this data into future forecasts," said Barbara Pohl, executive director of the department.

Voters in Colorado and Washington state legalized the possession and use of small amounts recreational marijuana by adults age 21 or older in 2012, even as marijuana remains an illegal narcotic under federal law.

Colorado opened its retail pot shops in January, and Washington is slated to follow suit later this year.

Under the Colorado legalization law, the first $40 million collected annually from the excise tax is earmarked for school construction and repairs.

The state legislature will decide how to spend any leftover money from marijuana taxes and fees.

Governor John Hickenlooper, who opposed the legalization of recreational cannabis, has told lawmakers he would like to see the bulk of state revenue derived from both recreational and medical pot sales to go toward addiction treatment and programs to prevent youths from using the drug.