LITTLE ROCK, Ark. (AP) - Two pharmaceutical companies that have said they don't want their drugs used in Arkansas' executions are asking to intervene in the court fight over whether the state can use a third lethal injection drug.

Fresenius Kabi USA and West-Ward Pharmaceuticals Corp. asked Thursday to file a friend of the court brief urging the court to uphold an order preventing Arkansas from using its supply of vecuronium bromide, one of three drugs used in the lethal injection process. A supplier has said it sold the drug to Arkansas to be used for medical purposes, not executions.

The companies have said they believe they manufactured the other two drugs Arkansas has for the executions, which are set for Thursday night.

Arkansas had scheduled eight executions over an 11-day period before the end of April, when its supply of one lethal injection drug expires. The first two executions were canceled because of court decisions. Legal rulings have put the others in doubt.