Busch was suspended from the Nationwide and Sprint Cup series races last weekend at Texas Motor Speedway after putting Ron Hornaday Jr. out of action in Friday's Camping World Truck event.
NASCAR announced the further sanctions Monday, saying in a statement that "if during the remaining NASCAR events in 2011 there is another action by the competitor that is deemed by NASCAR officials as detrimental to stock car racing or to NASCAR, or is disruptive to the orderly conduct of an event, the competitor will be suspended indefinitely from NASCAR."
The group said Busch's suspension had been lifted, so he can compete in Sunday's Sprint Cup race at Phoenix International Raceway.
He fell from seventh to 11th in the Chase for the Sprint Cup point standings and was mathematically eliminated from championship contention after sitting out last weekend's events.
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