Plans to launch new US exchange-traded funds (ETFs) in the platinum group metals sector are mired in delays, with no indication of when the commodity trading might start.

Industry observers have told Reuters that the intention to launch silver, pgm and crude oil ETFs - tracking the movement of prices with indexed stocks on exchanges - are still at a planning stage, with a lack of concrete details on how to proceed.

While there has been much interest in the idea and a solid basis of investor demand, little actual progress has so far materialised.

International Precious Metals Institute (IPMI)director George Gero admitted that registration for new stocks was "far from being filed".

"The concept is there, but there aren't any plans written up," he said.

"I would think you could have a pgms ETF and a silver ETF, if that were to be of interest in the future," he went on.

ETF provider Barclays Global Investors said recently that it was anticipating the ETFs getting off the ground at some point this year, but that now looks unlikely.

In addition some experts say they remain unconvinced about the level of demand for such a plan.

Leonard Kaplan, president of Prospector Asset Management, said that he expected silver would prove successful as an ETF, but said that the platinum and palladium would struggle because "the markets are simply too small".