Total U.S. money market mutual fund assets fell $14.68 billion to $2.679 trillion for the week ended Wednesday, Investment Company Institute said.

Assets of the nation's retail money market mutual funds fell $5.73 billion to $929.14 billion, the Washington-based mutual fund trade group said. Assets of taxable money market funds in the retail category fell $3.89 billion to $733.47 billion. Tax-exempt retail fund assets fell $1.84 billion to $195.67 billion.

Meanwhile, assets of institutional money market funds fell $8.95 billion to $1.750 trillion. Among institutional funds, taxable money market fund assets fell $8.13 billion to $1.653 trillion; assets of tax-exempt funds fell $820 million to $96.20 billion.

The seven-day average yield on money market mutual funds was 0.02 percent in the week ended Tuesday, unchanged from the previous week, said Money Fund Report. The 30-day average yield was also unchanged at 0.02 percent.

The seven-day compounded yield was flat at 0.02 percent, as was the 30-day compounded yield at 0.02 percent, Money Fund Report said.

The average maturity of the portfolios held by money market mutual funds was unchanged from the previous week at 44 days.

Bankrate.com 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 was unchanged at 0.13 percent from the previous week.

Bankrate.com said the annual percentage yield on six-month certificates of deposit was unchanged from the previous week at 0.22 percent.