From the start of October the index will replace its 5% bond issuer cap with a 3% cap and in addition will introduce a new cap of 20% on issuer countries.
This means the index will not provide more than 3% exposure to any one bond issuer, or more than 20% exposure to bond issuers domiciled in any one particular country.
iShares said the change to the index methodology was being made to provide an increased level of diversification within the index both across individual issuers and the overall level of issuers within individual countries.
The firm said this would lead to a greater level of diversification within the index and would help mitigate the risk of over-concentration in a particular country if it was downgraded to a sub-investment grade credit rating.
