The future mandate of Libya's sovereign wealth fund is uncertain following political unrest, a new report has said.

A new report from Preqin said the Libyan Investment Authority had been able to invest more freely after sanctions on the north African dictatorship were eased in recent years.

The fund controls an estimated $70 billion in total assets.

Clare Bowden, an analyst from the alternative investment research firm, wrote a sovereign wealth fund overview stating other countries in turmoil also have significant sovereign wealth funds including Algeria and Bahrain, in the report Collective Significance: Sovereign Wealth Funds Investing in Real Estate.

"Collectively these institutions have hundreds of billions of dollars in assets, and any changes in their investment policies or mandates could be felt widely," she wrote.

The report said global sovereign wealth funds have grown increased their aggregate assets under management by 11 per cent from $3.59 trillion in 2010 to $3.98 trillion in 2011.

In 2011 more sovereign wealth funds invested in all asset classes tabled including public equities, debt instruments, private equity, real estate, infrastructure and hedge funds, it was reported.

Public equities was the most widely used class, with 85 per cent of sovereign wealth funds involved in 2011, up from 79 per cent the previous year.

Infrastructure enjoyed the biggest rise in popularity with the number of sovereign wealth funds invested growing from 47 per cent in 2010 to 61 per cent in 2011.

Hedge funds continued to languish in popularity with only 37 per cent of sovereign funds invested in 2011, up slightly from 36 per cent in 2010.

The report found that the largest sovereign wealth funds were the most likely to invest in real estate.

Only 20 per cent of sovereign wealth funds with total assets less than $1 billion participated in property investment compared with more than 60 per cent of funds worth more than $10 billion in total assets.