A leading asset manager has said those with tracker investments could overexpose their funds to risks associated with investment in oil, pharmaceuticals, banks and commodities.

New Star Asset Management says investments in the FTSE 100's top ten could hold mixed fortunes.

It adds that tracker investments are fundamentally flawed.

Nearly half of the index's weightings comprise the top ten holdings in the FTSE 100, which mainly includes stocks in banks, oil and pharmaceuticals, the asset manager points out.

Almost a fifth of the FTSE is weighted between oil giants Shell and BP, while banks HSBC and Royal Bank of Scotland make up a tenth of the FTSE weighting.

Pharmaceutical companies GlaxoSmithKline and AstraZeneca make up nine per cent of weighting and mining stocks account for four per cent.

Vodafone and Unilever stocks make up five per cent and 1.2 per cent respectively.

Performance in these investment stocks has been described as extremely volatile over the last half-decade.

This is why New Star is urging private investors to note the associated investment risks that come with the FTSE 100 top ten companies.

It explains that when it comes to private investors, these risks are very significant and not often recognised.