As the first trials of BT's 21st Century Network come to a close in South Wales, the chief executive of BT Wholesale, the division responsible for 21CN, has announced that he is leaving the company. 

Paul Reynolds will leave BT in September to become the chief executive of New Zealand Telecom. 

Reynolds has been at BT since leaving university in 1983, and joined the board as head of BT Wholesale in 2001. He spearheaded BT's efforts to roll out broadband in the UK over the past six years.

The 21CN trial was significant in that it was the first of its kind in the world to carry phone calls over an all-IP next-generation network.

Following the trial, some 350,000 BT customers in the Cardiff area will migrate to 21CN over the next year.