Assets of the nation's 332 money market mutual funds rose $202 million in the latest week, the Investment Company Institute said.

The rise, to $213.5 billion in the seven-day period ended Wednesday, followed a $1.8 billion increase in the funds' assets the previous week, according to the Washington-based mutual fund trade group.

The figure set a two-year high last exceeded during the week ended Dec. 22, 1982, when assets reached $217.8 billion. The funds' assets hit a record high $232.6 billion in the week ended Dec. 1, 1982.

The Investment Company Institute said that in the latest week, assets of 182 general purpose funds fell $204.7 million to $64.52 billion, assets of 85 broker-dealer funds climbed $41.4 million to $92.08 billion, and assets of 65 institutional funds rose $365.3 million to $56.92 billion.

The seven-day average yield on the money market mutual funds fell in the week ended Tuesday to 8.38 percent from 8.60 percent the previous week, according to Donoghue's Money Fund Report, a trade journal based in Holliston, Mass.

The 30-day average yield also fell, to 8.67 percent from 8.84 percent, Donoghue's said.

Separately, the newsletter Bank Rate Monitor said its survey of 50 leading commercial banks, savings and loan associations and savings banks nationwide showed the average effective annual yield available on money market accounts fell to 8.52 percent as of Wednesday from 8.72 percent a week earlier.