Mineral exploration company Platinum Australia Ltd and earthmoving player NRW Holdings Ltd have been added to the S&P/ASX 200 list.
In a Standard and Poor's June quarterly rebalance, both companies will be added to the top 200 list as of June 20.
Meanwhile, iron ore miner Mount Gibson Iron Ltd has been boosted to the S&P/ASX 100 list. The company has a market capitalization of $2.4 billion.
S&P said there were few securities eligible for inclusion into the S&P/ASX 200 portfolio this quarter. In spite of several stocks meeting the necessary size requirements, the essential liquidity hurdles were not met.
"We are seeing strong liquidity limited to stocks at the top-end of the market, with small-cap securities trading thin on a relative basis," said Simon Karaban, associate director at Standard & Poor's Index Services.
"The S&P/ASX 200 is a tradable instrument, therefore it is paramount that liquidity is firmly controlled, therefore restricting the number of stocks that can be promoted."
