Exchange-traded fund (ETF) provider Australian Index Investments (Aii) has seen $3 million flowing into its resources ETF since the product's launch in March this year.

"We have now experienced three-fold growth in the size of our resources ETF, with two additional baskets of units needing to be issued to the market to keep up with the demand," Aii managing director Jim Socratous said.

"Although many feared the mining tax debate would scare investors away, this certainly does not seem to be the case when looking at our ETF volumes," he said.

About 70 per cent of transactions took place through online brokers, which indicated a strong interest from self-managed super funds (SMSFs) and self-directed investors, Socratous said.

But Socratous said the product had also received support from financial advisers.

"The feedback we have received is that sector-specific ETFs are attractive to brokers and advisers as it still allows for active, strategic investment recommendations," Socratous said.

"Most benchmark-based ETFs are of a 'set and forget' nature and therefore may not really fit with a traditional broking model."
 
"As Aii ETFs allow brokers and advisers to recommend one sector over another, we are finding the market is much more receptive than we had anticipated."

The Aii S&P/ASX 200 Resources ETF has been the most highly traded Aii ETF, with 45 per cent of volume and 60 per cent of value of all trades.

The financials and metals and mining ETFs were equal second with 16 per cent each.

Socratous expected interest in the financials ETF to increase due to the recent addition of a second market maker.

Earlier this month, Aii signed on Citi in addition to Susquehanna as a market maker.

Market makers provide liquidity by acting as both buyer and seller of ETF units.