* Proposed legislation would regulate marijuana like alcohol
* Sales would be subject to 50 percent federal tax
* Effort follows votes to legalize in Washington state, Colorado (Adds details on bills, reaction)
By Susan Heavey
WASHINGTON, Feb 5 (Reuters) - U.S. states would be free to decide how to regulate marijuana just like beer and wine without running foul of federal law under legislation being proposed by two Democratic lawmakers.
Earl Blumenauer of Oregon and Jared Polis of Colorado plan to introduce two bills in the House of Representatives on Tuesday amid a growing movement to legalize pot for personal use, whether recreational or medical.
One bill would end a federal ban on marijuana and give states jurisdiction over its use and regulate it in a similar way to alcohol sales, with federal oversight. The other would levy a federal tax on its sale, the congressmen said in a statement.
The bills will likely face significant difficulties in the House, where conservative Republicans hold a majority and control what legislation moves forward. A similar, bipartisan effort by other representatives failed to gain traction in 2011.
Washington state and Colorado voted to legalize marijuana in 2012 but now face questions on how to implement their laws while national authorities still consider the drug illegal. Illinois lawmakers also considered legalizing pot for medical use last year, but the effort lacked support.
Eighteen states, including California, Oregon and Washington DC, allow marijuana sales for medical use to help patients cope with pain and other chronic conditions, according to the National Conference of State Legislatures, which tracks state laws.
Last year's votes in Washington state and Colorado have buoyed those who support easing access to marijuana, the most commonly used illegal drug in the United States. Polls show a majority of Americans support legalizing pot.
Critics say that despite widespread use and acceptance, the drug, derived from the cannabis plant and usually smoked, carries health risks, especially for youth. And they question whether it has benefits for medical use.
The bill put forward by Polis would require the U.S. attorney general to "decriminalize" pot within 60 days of the passage of the legislation. It would require sellers to have permits and transfer oversight to the Bureau of Alcohol, Tobacco, Firearms and Explosives, rather than the Drug Enforcement Administration.
Blumenauer's bill would impose a federal tax on pot producers and sellers equal to 50 percent of the product's sale price.
Advocates on both sides of the issue are waiting to see how federal authorities will respond to the moves in Washington state and Colorado.
The U.S. Justice Department has yet to clarify its stance, but President Barack Obama has said it does not make sense for the federal government to focus on recreational drug users in such states, given limited government resources and growing public acceptance.
On Tuesday, a spokeswoman for the Justice Department said it had yet to review the proposed bills and was still looking at the initiatives in Colorado and Washington state.
The Marijuana Policy Project, which has been pushing to relax the U.S. stance on the drug for years, welcomed the proposals as a way to move the pot trade toward regulated sellers and away from drug cartels and criminals.
"Marijuana prohibition has proven to be just as ineffective, wasteful, and problematic as alcohol prohibition," said Steve Fox, the group's director of government relations.
U.S. drug officials have classified marijuana as an illegal drug with no accepted medical use and a high potential for abuse since 1970. (Additional reporting by David Ingram; Editing by Howard Goller and Philip Barbara)