NEW YORK (AP) _ Assets of the nation's 667 retail money market mutual funds rose by $431.6 million in the latest week to $720.15 billion, the Investment Company Institute said Thursday.

Assets of the 398 taxable money market funds in the retail category grew by $1.38 billion to $588.58 billion for the week ended Wednesday, the Washington-based mutual fund trade group said. The 269 tax-exempt fund assets fell by $946.5 million to $131.57 billion.

Assets of the 349 institutional money market fell by $7.56 billion to $389.48 billion for the same period. Among institutional funds, the 285 taxable money market fund assets fell by $6.90 billion to $348.98 billion; assets of the 64 tax-exempt funds fell by $651.7 million to $40.51 billion.

Total money market assets stood at $1.110 trillion for the week.

Assets for the previous week were revised to $1.117 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 5.05 percent from 5.08 percent the previous week, said IBC's Money Fund Report, a trade journal published in Ashland, Mass., by IBC Financial Data Inc. The 30-day average yield fell to 5.11 percent from 5.13 percent, IBC Financial Data said.

The seven-day compounded yield rose to 5.18 percent from 5.21 percent the previous week, and the 30-day compounded yield fell to 5.24 percent from 5.26 percent, IBC Financial Data said.

The average maturity of the portfolios held by money funds remained unchanged at 52 days, IBC Financial Data said.

The newsletter Bank Rate Monitor 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 to 2.55 percent from 2.56 percent as of Wednesday.

The North Palm Beach, Fla.-based newsletter said the annual percentage yield available on interest-bearing checking accounts remained at 1.23 percent.

Bank Rate Monitor said the annual percentage yield was 4.77 percent on six-month certificates of deposit, down from 4.78 percent the previous week. Yields were 5.02 percent on 1-year CDs, down from 5.03 percent; 5.17 percent on 2 1/2-year CDs, down from 5.19 percent; and 5.32 percent on 5-year CDs, down from 5.35 percent.