Christchurch's Lyttelton Port Board has approved the 800-million-dollar Te Awaparahi Bay Investment Case expansion plan

It will let the port berth larger vessels and lift the annual container capacity from about 520-thousand standard 20-foot containers, to 850-thousand.

CEO Graeme Summer says it's a vital development for Canterbury and the South Island economy, allowing increased trade volumes at the port manage.

The case will be presented to port owner and council investment arm Christchurch City Holdings early next year.