* State pot law does not regulate private employers -judge
* Wal-Mart justified in firing employee for positive test
NEW YORK Feb 11 A federal judge in Michigan on Friday upheld Wal-Mart Stores Inc's dismissal of an employee for testing positive for marijuana, even though he was using the drug under the state's medical marijuana law.
Judge Robert Jonker wrote that while the state law was meant to provide some limited protection for medical marijuana users from state arrest and prosecution, it does not regulate private employers.
Former Wal-Mart employee Joseph Casias said he was using the marijuana to treat pain from an inoperable brain tumor and sinus cancer, and was doing so legally, with a medical marijuana registry card.
After twisting his knee at work, Casias submitted to a drug test, administered under a Wal-Mart policy requiring tests for all employees injured on the job. When he tested positive, he was fired.