UPDATED: 4.06PM After six months of negotiations, including a bus strike causing traffic chaos, Auckland bus companies and unions have come to an agreement.

Rotating rosters were introduced in July last year, significantly changing the nature of many drivers' working hours.

This meant some drivers were working 11-hour days with short breaks and inadequate toilet breaks.

Under the new agreement between New Zealand Bus and unions FIRST and Auckland Tramways, wages would increase by two per cent from November last year and a further two per cent in November this year.

This meant drivers would be getting a back pay of wages from November last year.

It also allows drivers to work non-rotational rosters.

FIRST Union bus organiser Rudd Hughes said he was pleased with the new agreement but the pay increase was not quite as much as their members wanted, but it was never really about the pay.

"It was really about getting things like good consultation processes, we've absolutely got that, and giving the option around what type of rosters people wanted.

"Some important progress has been made on non-wage areas and delegates will now be recommending to our members that this offer is ratified.

"It's a reasonable compromise," he said.

Mr Hughes said they're heading round to all the depots over the next two weeks, to make sure everyone's happy.

"We will be having a vote at those meetings and they will decide whether or not to accept it or not. If they don't accept it, it's back to the table, if they do accept it it's all go."

Gary Froggatt, President of Auckland Tramways, said: "Tramways delegates will be recommending to our members that the offer made by the company is accepted."

NZ Bus manager Shane McMahon said: "We have reached a good agreement which sees a real wage increase for our people. Once ratified this will be a great result for our drivers and customers."

Working conditions and pay issues have been a long-running source of tension between NZ Bus and unions.

Rotating rosters were introduced in July last year, significantly changing the nature of many drivers' working hours.

Some shifts were nearly 11 hours. In one example given to the Authority, unions showed how a driver would be required to come in at 6.20am, finishing at 6.02pm then returning the next day at 7.40am. After finishing their second shift at 7.01pm, the driver would be expected to come in for a third shift at 5.50am the next day, finishing at 3.02pm.

The short breaks between long shifts as well as inadequate toilet breaks while drivers were on shift were some of the union's main concerns in relation to working conditions.

The new rosters also had stretches where drivers would work five or six weekends in a row, something unions said would greatly impact on drivers' ability to spend time with their families.

On February 19 bus drivers went on strike, demanding a pay rise and better breaks on and between shifts.

NZ Bus said its drivers were paid $20.40 an hour plus overtime, and was offering another 35 cents an hour but unions rejected that offer. First Union asked for $21 an hour for drivers.

The strike was followed by a round of stopwork meetings in February.