Norway’s KLP has said that not only has its membership increased by 100,000 in the first half of this year as a knock-on effect of the decision by Storebrand and DnB Livsforsikring to withdraw from the public occupational pensions market, but a further 50,000 members will join before the end of the year.

In its second-quarter interim report, the public service pension provider said it took on an extra 100,000 members by the end of June – a figure it previously predicted for the whole of 2014 – including 17,000 pensioners.

Its active membership reached 401,249 at the end of May.

In the first half, it said 42 local authorities and around 50 enterprises had taken their pension scheme to KLP, as life insurance companies Storebrand and DnB Livsforsikring left the public occupational pensions market.

The membership expansion is now set to continue in the next few months.

KLP said a further 16 local authorities and around 150 enterprises had decided to transfer to KLP, meaning it would gain another 50,000 new members in the last six months of the year.

Initially, it said, six local authorities had decided to transfer on 1 July this year.

However, after the Pensions Office (Pensjonskontoret) – which supervises the provision of public sector occupational pensions within the Norwegian Association of Local and Regional Authorities (KS) area – had decided to allow other transfers at the half-year point, another 10 authorities had followed suit, it said.

Sverre Thornes, KLP’s chief executive, said: “These transfers to KLP represent one of the largest influxes of new members to KLP’s pensions schemes ever.”

He said the institution was facing the changed market situation by continuing to focus on value creation through good returns, low costs and good service.

“It is important for us,” he added, “to show public sector employees and our customers we take good care of pension assets by providing good results.”

The fact the growth in pensioners is happening without increasing staff numbers means lower costs for KLP’s clients in the future, he said.

Reserves increased by NOK21.6bn (€2.6bn) in the first six months of this year because of the new customers transferring in.

KLP’s solvency capital stood at NOK59.5bn at the end of June, up from NOK47bn at the same point in 2013, and equated to 18.6% of insurance funds with interest guarantee, up from 17.2%.

The group posted a return on capital rises to 3.6% in the first half, compared with 2.8% in the same period last year, saying shares, short-term bonds and property had been the most important contributors to overall returns.

Total assets for the KLP Group rose by around 10% to NOK442bn from NOK399.3bn at the end of December.