Boutique fund manager Hyperion Asset Management is set to close its $1.8 billion broad-cap offering to new institutional investors due to strong inflows from existing clients.

Hyperion managing director Manny Pohl said the broad-cap strategy, which manages among other funds the Hyperion Australian Growth Companies Fund, was "likely to be soft closing in the near future", meaning only existing investors would be able to invest additional funds in the strategy.

"Given our good performance during the global financial crisis, our existing client base has given us additional money to manage," Pohl told Investor Weekly.

"We will always look after our existing clients, which means we would be looking to limit the number of new clients we take on board."

Hyperion's ASX 300 offering is an alternative to the broad-cap strategy and still has available capacity of $2 billion.

Pohl said the manager's style of investing lent itself to an ongoing evaluation of capacity.

"Because we are agnostic to size of company, the capacity constraint affects all our mandates including our Hyperion Growth Companies Fund," he said.

The Australian Growth Companies Fund invests in growth-style companies and is dominated by organisations that own high-quality business franchises, with above average growth potential, and low levels of gearing with predictable medium to long-term earnings streams.
The fund is highly concentrated, typically 20-30 stocks, with low turnover.

In addition to the Australian Growth Companies Fund, its retail offering includes listed investment company Hyperion Flagship Investments and Hyperion manages institutional mandates for industry funds, including Health Super and Auscoal.