Perfectly ordered nanotubes (NTs) displaying a limited number of defect-free B-C-N shells (typically 2-4) were synthesized from CVD C NTs and a mixture of boron oxide and gold oxide placed in a flowing N-2 atmosphere at 1950 K. The NTs were analyzed using field emission conventional and energy-filtered (Omega filter) high-resolution electron microscopes, and electron energy loss and energy dispersive X-ray spectrometers. NTs with inner diameters of 0.9-4.0 nm were frequently assembled in bundles consisting of several tubes and extending up to 1-2 mum in length. Two-terminal transport measurements on individual B-C-N nanotube bundles were carried out in-situ in a Fresnel projection microscope. The bundles displayed semiconducting behavior with an estimated band gap of similar to1 eV. (C) 2002 Published by Elsevier Science B.V.