NEW ORLEANS — Federal authorities say a rig is being positioned to drill a relief well for a gas leak in the Gulf of Mexico, and a permit is in the final stages of review.

The Bureau of Safety and Environmental Enforcement said Saturday that it's reviewing Walter Oil & Gas Corporation's permit to drill the relief well off the Louisiana coast.

The relief well could intercept the leaking well and seal it with drilling mud and cement.

The leak is from a gas rig that blew wild Tuesday morning. Spewing gas ignited that night, burning the rig owned by Hercules Offshore Inc.

Authorities believe that sand and sediment clogged the well late Wednesday, shutting off the gas flow in what is referred to as a "bridge over."