Chapman Tripp has the lead role on the expected $726 million initial public offering of New Zealand oil company Z Energy Ltd.

The Wellington-based company, formerly the New Zealand subsidiary of Royal Dutch Shell Plc., operates a chain of 200 gas stations and has a 17 percent stake in the country’s only oil refinery. Z Energy accounts for about a third of all fuel sold in New Zealand.

The company is planning to sell up to 60 percent of its shares on the Australian and New Zealand stock exchanges. It is part of a spate of major IPOs in New Zealand. In May, state-owned Mighty River Power Ltd. held a $1.6 billion listing. A $2.4 billion IPO for state-owned electrical utility Meridian Energy Ltd. is planned for later this year.