Total U.S. money market mutual fund assets fell $13.11 billion to $2.652 trillion for the week that ended Wednesday, the Investment Company Institute said Thursday.

Assets of the nation's retail money market mutual funds fell $2.72 billion to $920.11 billion, the Washington-based mutual fund trade group said. Assets of taxable money market funds in the retail category fell $2.33 billion to $725.86 billion. Tax-exempt retail fund assets fell $390 million to $194.25 billion.

Meanwhile, assets of institutional money market funds fell $10.38 billion to $1.732 trillion. Among institutional funds, taxable money market fund assets fell $8.76 billion to $1.639 trillion; assets of tax-exempt funds fell $1.62 billion to $93.65 billion.

The seven-day average yield on money market mutual funds was 0.03 percent in the week that ended Tuesday, unchanged from the previous week, said Money Fund Report, a service of iMoneyNet Inc. in Westborough, Mass.

The 30-day average yield was also unchanged from last week at 0.03 percent. The seven-day compounded yield was flat at 0.03 percent. The 30-day compounded yield was unchanged at 0.03 percent, Money Fund Report said.

The average maturity of the portfolios held by money market mutual funds fell to 45 days from 46 days in the previous week.

The online service said its survey of 100 leading commercial banks, savings and loan associations and savings banks in the nation's 10 largest markets showed the annual percentage yield available on money market accounts rose 0.14 percent from 0.13 percent in the previous week.

The North Palm Beach, Fla.-based unit of Bankrate Inc. said the annual percentage yield available on interest-bearing checking was unchanged from the week before at 0.06 percent. said the annual percentage yield on six-month certificates of deposit was unchanged from the previous week at 0.22 percent. The yield was unchanged at 0.34 percent on one-year CDs; and was flat at 0.53 percent on 2 1/2-year CDs; and unchanged at 1.15 percent on five-year CDs from the prior week.