If orders continue to increase, the company may eventually re-employ staff laid off, although it is cautious about when that might happen.
Yesterday, the National Distribution Union (NDU) welcomed the decision and praised Summit's "positive attitude" to a worldwide economic recession which led to a collapse in orders for yarn.
Problems started to emerge at the mill, owned by Sumitomo Corporation of Japan, in February and extensive negotiations between the company, staff and their unions followed.
Summit called for voluntary redundancies, resulting in 50 workers being laid off.
In April, it joined the Government's nine-day fortnight scheme, which saved another 57 jobs at the plant.
Staff were working shifts of nine hours, four days on-four days off.
"Since then, there's been a small but promising increase in orders from Australia that's sufficient to return us to 10-hour shifts," Summit director Ricky Hammond-Tooke said.
This was still subsidised under the nine-day fortnight scheme.
"It essentially returns our people to last November, when shifts at the plant were reduced from 12 hours to 10 hours in response to an earlier downturn in orders," he said.
It was too early to be thinking of any return to 12-hour shifts or re-employing any of those who took voluntary redundancy, Mr Hammond-Tooke said.
The Government scheme was due to run until October, when the company would better able to assess forward orders.
"We know our customers have been running down inventories and at some stage they'll be looking at resuming some level of orders, but how that translates into actual business remains to be seen," he said.
Otago-Southland organiser for the National Distribution Union Ken Young said members would be delighted with the increase in hours.
"Although still early days, we hope orders and production will increase so workers will be able to return to their 12-hour shift system and laid off workers re-employed," Mr Young said.
Engineering, Printing and Manufacturing Union lead organiser John Gardner said the move was good progress.
"We're hoping this is the first sign of recovery for Summit and will be doing whatever we can to assist our members through the process," Mr Gardner said.
