Metro Performance Glass, which has more than half the country's glass processing market, will join the stock market's benchmark index later this month, replacing gold miner OceanaGold Corp.

Auckland-based MetroGlass, which listed on the NZX in July, will join the NZX 50 Index on Dec. 22, the NZX said in a statement. OceanaGold, which is also listed in Australia and Canada, will leave the benchmark after index after failing to meet liquidity criteria in two consecutive quarterly reviews.

Joining the NZX 50 means institutional investment funds that track indices will have to buy shares in the two new companies, while exiting their holdings in the departed. The stock market operator reviews the make-up of the benchmark index each quarter.

Shares of MetroGlass were unchanged at $1.86 today, up from its $1.70 initial public offer price, and valuing the company at $344.2 million. OceanaGold shares fell 3.3 percent to $2.35 on the NZX today, valuing the miner at about $709 million.