NEW YORK (AP) - Assets of the nation's retail money market mutual funds fell by $1.86 billion in the latest week to $1.045 trillion, the Investment Company Institute said Thursday.

Assets of taxable money market funds in the retail category fell by $2.14 billion to $855.34 billion for the week ended Wednesday, the Washington-based mutual fund trade group said. Tax-exempt fund assets rose by $279.8 million to $189.69 billion.

Assets of institutional money market funds rose by $21.69 billion to $1.215 trillion for the same period. Among institutional funds, taxable money market fund assets rose by $22.02 billion to $1.135 trillion; assets of tax-exempt funds fell by $326.1 million to $80.61 billion.

Total money market assets stood at $2.260 trillion for the week.

Assets for the previous week were revised to $2.240 trillion to reflect reporting errors and a change in the number of funds reporting.

The seven-day average yield on money market mutual funds fell in the week ended Tuesday to 1.24 percent from 1.27 percent the previous week, said Money Fund Report, a service of iMoneyNet Inc. in Westboro, Mass. The 30-day average yield fell to 1.25 percent from 1.26 percent, according to Money Fund Report.

The seven-day compounded yield fell to 1.25 percent from 1.28 percent the previous week, and the 30-day compounded yield fell to 1.26 percent from 1.27 percent, Money Fund Report said.

The average maturity of the portfolios held by money funds was 53 days, down from 55 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 was 1 percent as of Wednesday, unchanged from a week earlier.

The North Palm Beach, Fla.-based unit of Bankrate Inc. said the annual percentage yield available on interest-bearing checking accounts was unchanged at 0.42 percent.

Bankrate.com said the annual percentage yield was 1.58 percent on six-month certificates of deposit, down from 1.60 percent the previous week. Yields were 1.81 percent on 1-year CDs, down from 1.84 percent; 2.43 percent on 2 1/2-year CDs, down from 2.48 percent; and 3.63 percent on 5-year CDs, down from 3.72 percent.