The present invention relates to a novel polyamide alloy composition that is useful for forming objects that may be used for the storage and transport of fluids. The polyamide alloy is a blend of at least one polyamide and at least one modified polyolefin having both medium to hard and soft domains. The polyamide forms the continuous phase of the alloy. The alloy may also contain, and preferably does contain, a thermal and light stabilization compound, at least one unmodified polyolefin, and at least one plasticizer. The polyamide alloy composition is useful in forming tanks, hoses and tubes used in the transport of liquid or gaseous fluids, including fluids under pressure.