The Commerce Commission has found Wilson Parking New Zealand's 2013 acquisition of a rival's parking assets hasn't substantially crimped competition and deemed that public transport will keep a lid on any price hikes.

The antitrust regulator launched its investigation into the purchase by Wilson, owned by Hong Kong's Kwok family, of about 60 percent of locally-owned Tournament Parking's car parking licences and management contracts, on concern it would reduce competition. At the time, Wilson had more than 100 sites across New Zealand, while Tournament operated more than 80 locations, making them the biggest and second-biggest car park providers respectively.

The commission's focus was on city centres, in particular Auckland's Parnell Rise and Symonds Street areas, where the purchase reduced the amount of competition Wilson faced, the regulator said in a statement. It found that while the acquisition had "removed a competitive constraint" a customer survey reported there was enough public transport in the area that if parking increased by 5 percent they would abandon driving.

"The intent of customers to switch to public transport if car park prices rise is inconsistent with comments from industry participants, and it isn't our view that public transport will always curb car parking prices," chair Mark Berry said. "However, we did not uncover strong evidence to contradict the survey results in these specific areas, where public transport is well-used and convenient.

"In our view, the evidence does not support a conclusion that Wilson Parking's purchase of Tournament substantially lessened competition in the areas where we had concerns," Berry said.

According to its 2013 financial statements lodged with the companies office, Wilson paid $29.4 million for Tournament's assets. The following year, Wilson reported a net profit of $2.8 million in the year ended June 30, 2014, up from $2.2 million in 2013, while sales rose 37 percent to $66.3 million.