State lawmakers and Gov. Lincoln Chafee announced a compromise Thursday that they say will allow three medical marijuana dispensaries to open soon without the risk of a federal prosecution.

The deal, which must be approved by the state�s General Assembly, would limit the amount of marijuana dispensaries could possess. Chafee blocked three state-approved dispensaries from opening last year after the state�s top federal prosecutor warned that large-scale drug distribution could run afoul of federal drug laws.

�Our main concern is getting compassion centers up and running for the many suffering patients who still have no legal way to obtain their prescription medicine,� said state Sen. Rhoda Perry, D-Providence, one of the lawmakers who crafted the compromise. �It�s been three years now since we approved compassion centers. That�s a long time for patients to wait for relief from pain and illness.�

The compromise is good news for the 4,416 people now enrolled in the state�s medical marijuana program, according to JoAnne Leppanen, executive director of the Rhode Island Patient Advocacy Coalition, a group which called on Chafee to allow the dispensaries to open.

Rhode Island already allows qualified patients to possess small amounts of marijuana to treat conditions including chronic pain, severe nausea, seizures and multiple sclerosis. Lawmakers approved the compassion center law after patients said there were few safe and reliable sources for medical marijuana.

�This is a huge relief,� Leppanen said. �The dispensaries have had their licenses for almost a year now. We can�t get them open soon enough.�

Leppanen said she hopes the dispensaries could be open within a few months.

It would be up to the state�s Department of Health to set limits on how much marijuana a dispensary may possess. Department spokesman Peter Hanney said Health Director Michael Fine plans to hold public hearings on the limits if the bill passes. He said there�s no estimate as to how long the process might take.

Last spring, federal prosecutors wrote to officials in several states contemplating dispensaries that large-scale medical marijuana operations could face criminal prosecution for drug crimes. The prosecutors said they wouldn�t target medical marijuana users who grow or possess small amounts for personal use.

In response, Chafee blocked the dispensaries from opening and said he would work on finding a workable compromise.

�I look forward to passage of a bill that will avoid federal intervention and bring needed medicinal relief to those who stand to benefit,� Chafee said in a statement Thursday.

A spokesman for U.S. Attorney Peter F. Neronha of Rhode Island said Thursday that Neronha�s office has yet to review the proposed compromise.

The three dispensaries to be licensed are Thomas C. Slater Compassion Center in Providence, Summit Medical Compassion Center in Warwick and Greenleaf Compassionate Care Center in Portsmouth.