NETHERLANDS - Approximately 30,000 former port workers will see their pension benefits increased by more than 13.5% in the wake of a long-running dispute over Aegon's takeover of Optas, their pension provider.

The one-off increase will apply to active and deferred participants of the port workers' pension fund PVH who have accrued pension rights before 1998, according to a new asset management subsidiary of their representative body SBPVH.

SBPVH said the €225m of the €500m compensation that has been allocated to this group of participants would be paid next spring.

The pensions of the remaining three groups - with 18,000 participants in total - will be increased in three stages before the spring of 2012, according to the SBPVH, which conceded that details about the pay-out still needed to be finalised.

The dispute over ownership rights to the pension plan's assets arose after the Optas Foundation - the pension fund's commercial life insurer and pension provider - was taken over by Aegon in 2007 for €1.5bn.

The foundation - which intends to use the proceeds of the sale for social and cultural purposes, such as art subsidies - disputed a claim from harbour employers and employees that the assets should be used to benefit the policyholders.

In April 2010, the harbour workers' lobbying organisation settled the case after the Optas Foundation offered a one-off contribution of €500m to Optas Pensioenen NV, now part of Aegon, to improve the pension rights of 48,000 policyholders.

Two years earlier, the SBPVH had turned down an offer from Optas Foundation to pay €350m to improve pension rights.

According to Niek Stam, chairman at the SBPVH, the harbour workers will keep their claim to the €831m of 'constricted assets' (beklemd vermogen), which also went to Aegon as part of the Optal deal.

"We are entitled to the money, which was meant as a general financial buffer for the harbour workers," he said, adding that he would be open to compromise.

Stam has launched a campaign to put pressure on the insurer, as "we don't have the resources or the time for a legal procedure on the merits of the case".

Last April, Aegon denied the constricted assets would be subject to talks.