As regulators consider additional moves to shore up money market funds, like requiring funds to set aside reserves, Treasury Strategies recommends companies protect themselves by reworking their investment policies to track specific measures of diversification. The consultancy has come up with seven parameters, such as the portion of its assets a company invests in a single fund or fund family, or any one issuer or country.

Each parameter includes a range that companies can fine-tune according to their own level of risk tolerance. For example, one parameter suggests limiting the amount the company invests in any one fund to between 10% and 35% of the company's assets. "So the more risk-averse companies would be advised, for example, to keep just 10% in any single money-market fund," says Michael Gallanis, a partner at Treasury Strategies.

Companies might not need all the parameters. For example, a company that doesn't invest outside the U.S. wouldn't need to consider how much to invest per country.