The retail banking arm of Dutch bank ABN Amro has posted an underlying profit of EUR338m for the first quarter of 2015, up 49% compared to EUR226m a year ago.

The unit’s operating income rose by 3% to EUR978, versus EUR952m in the first quarter of 2014, primarily driven by improved mortgage margins, partly offset by lower average volumes on mortgages.

The division’s quarterly net interest income grew by 3% to EUR836m compared with EUR810m in the year ago quarter.

The retail banking arm’s operating expenses stood at EUR493m, indicating a marginal rise of 1% from EUR488m in the previous year quarter.

Overall, the group’s underlying profit for the first quarter was EUR543m, up 44% from EUR378m in the year ago first quarter.