Are whole market tracker funds halal?

Salam,

Is it halal to invest in funds that track the whole market? From my limited reading so far I understand that if the majority of profits from a company are deemed halal then you can invest in them, even if some of their money is not derived in a halal way. Can this be generalised to markets as a whole? For example the FTSE 100. If so, what would be a good way to calculate how much if the profit needs to be purified?

Jazak Allahu Khair for you response.
Ahmed

Assalaamu alaykum,

Kindly read my research paper on this subject on the following link: