Total assets of money market mutual funds fell by $8.36 billion to $3.319 trillion for the week ending Dec. 2 as retail and institutional investors sought out greater yields, according to the Investment Company Institute.

Retail money market fund assets lost $3.87 billion to settle at $1.078 trillion. Among retail money funds, taxable assets fell $4.18 billion to $840.71 billion, while tax-exempt fund assets climbed by $210 million to $236.93 billion.

Institutional money fund assets fell by $4.39 billion to $2.242 trillion during the same period. Among institutional funds, taxable assets fell $6.12 billion to $2.072 trillion, while tax-exempt fund assets climbed $1.73 billion to $170.10 billion.

The seven-day average yield for money market funds remained flat at 0.03% for the week ending Dec. 1, according to iMoneyNet Inc.'s Money Fund Report. The 30-day average yield was also unchanged at 0.04%.

The seven-day compounded yield was unchanged at 0.03%, as was the 30-day compounded yield, stuck at 0.04%.

The average maturity of money fund portfolios was 51 days, down from 53.