TORONTO -- The Canada Pension Plan Investment Board said it earned a 3.4 per cent return in its latest quarter.

The board, which manages portfolios on behalf of the Canada Pension Plan, had net assets of $234.4 billion for the period ended Sept. 30.

That was up from $226.8 billion at the end of the previous quarter.

It says the majority of the increase, or $7.5 billion, was due to net investment income.

The remaining $100 million was net CPP contributions.

CPPIB invests money not currently needed by the Canada Pension Plan to pay benefits.

The board says it's building an investment portfolio with a "exceptionally long investment horizon" and that is a more indicative of its performance than the returns of any given quarter or year.

"We continue to realize the benefits of a globally diversified, resilient portfolio that is designed to deliver superior returns over the long term," said president and chief executive Mark Wiseman in a statement.

During the quarter, CPPIB closed a deal to acquire a 39 per cent stake in Interparking, one of Europe's largest parking lot management companies, for about $546 million.

Based in Brussels and with operations across nine countries in Europe, Interparking owns 657 car parks in 350 cities.