Film publicist Claire Raskind said the preview would include scenes of hobbits and computer-generated special effects. The footage was part of a "showreel" screened at ShoWest, a presentation for major United States cinema owners earlier this year, and at a party in Los Angelees hosted by Wellington Mayor Mark Blumsky and Waitakere Mayor Bob Harvey to encourage mor films to be made in New Zealand.
Ms Raskind said producers decided to broadcast part of the showreel because of requests from Lord Of The Rings fans.
The official website says the footage will be shown on April 7 at noon Los Angeles time - 7am on April 8 in New Zealand.
A Lord Of The Rings crew will spend about a month filming in Tongariro National Park around Mt Ruapehu from this weekend.