The B747 was being radar vectored to a long left base to runway 34. The controller became anxious during the aircraft's approach as it was well above a normal descent profile. Despite prompting from the controller, the crew indicated that the descent profile was satisfactory. As the aircraft entered a long final approach, the captain asked for a left orbit to lose altitude as they were too high and not yet in the landing configuration. The B200C was also tracking in from the south-west for left base to runway 34, and about 10 NM behind the B747. Because of this potential confliction, the controller refused the captain's request and directed the B747 onto a heading of 090 degrees and restricted its descent to 2,000 ft. The B747 crew did not hear or understand the heading restriction, did not read back the radar heading and continued in a right orbit. The controller ordered a reversal of the turn, with which the B747 crew complied. In the mean time the lateral and vertical separation standards of 3 NM and/or 1,000 ft were compromised between the B200C and the B747. Both crews were given traffic information on the other aircraft and visual separation was maintained until the radar separation standards were once again established. During the telephone interview, the B747 captain said that the first officer was flying and a little slow in configuring the aircraft. He (the captain) was handling the radio and until entering final approach was still convinced that an approach could be made with track lengthening. He asked for an orbit to the left being unaware of the position of the following aircraft. He said that they did not hear the heading restriction and assumed that a right orbit was acceptable. The controller made an error of omission in not obtaining a readback of the heading. The controllers work load was light at the time of the incident. FACTORS 1. The B747 crew of Air France 144 misjudged their descent profile and entered the final approach too high to complete a normal landing. 2. The B747 crew did not follow the instructions issued by ATC. 3. The controller did not obtain a readback of the heading information.