NEW YORK (AP) _ Assets of the nation's retail money market mutual funds fell by $7.75 billion in the latest week to $1.088 trillion, the Investment Company Institute said Thursday.

Assets of taxable money market funds in the retail category fell by $7.36 billion to $896.85 billion for the week ended Wednesday, the Washington-based mutual fund trade group said. Tax-exempt fund assets fell by $392.2 million to $191.33 billion.

Assets of institutional money market funds fell by $33.09 billion to $1.218 trillion for the same period. Among institutional funds, taxable money market fund assets fell by $32.62 billion to $1.133 billion; assets of tax-exempt funds fell by $466.7 million to $84.33 billion.

Total money market assets stood at $2.306 trillion for the week.

Assets for the previous week were revised to $2.347 trillion to reflect reporting errors and a change in the number of funds reporting.

The seven-day average yield on money market mutual funds rose in the week ended Tuesday to 1.59 percent from 1.58 percent the previous week, said Money Fund Report, a service of iMoneyNet Inc. in Westboro, Mass. The 30-day average yield fell to 1.65 percent from 1.70 percent, according to Money Fund Report.

The seven-day compounded yield rose to 1.60 percent from 1.59 percent the previous week, and the 30-day compounded yield fell to 1.66 percent from 1.72 percent, Money Fund Report said.

The average maturity of the portfolios held by money funds was 56 days, down from 58 days, said Money Fund Report.

The online service 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 fell to 1.14 percent as of Wednesday from 1.15 percent a week earlier.

The North Palm Beach, Fla.-based unit of Bankrate Inc. said the annual percentage yield available on interest-bearing checking accounts held at 0.48 percent.

Bankrate.com said the annual percentage yield was 1.88 percent on six-month certificates of deposit, down from 1.89 percent the previous week. Yields were 2.14 percent on 1-year CDs, down from 2.15 percent; 2.95 percent on 2 1/2-year CDs, unchanged; and 4.09 percent on 5-year CDs, up from 4.07 percent.