* Daily average trades up 57 pct in Aug from year-ago
* Client assets flat from July at $1.65 trillion
* optionsXpress trading volumes up 17 pct in Aug from July
Sept 15 (Reuters) - The number of average daily trades at U.S. discount broker Charles Schwab Corp (SCHW.N) soared 35 percent in August from July and 57 percent from a year earlier as traders scrambled to react to increased market volatility.
Schwab said its clients made an average of 545,300 daily trades in the month, up from 404,100 in July and 346,000 in August 2010.
Total client assets were $1.65 trillion at the end of the month, flat from July, and up 19 percent from a year earlier.
The downgrading of the U.S. credit rating by Standard & Poor's in August, as well as worries about U.S. and European debt levels, shook markets and investors scrambled to react, sending trading levels higher. [ID:nN1E774236]
At the same time, doubts over the health of the global economic recovery increased, sending equities markets lower.
Net new assets brought to the company by new and existing clients in August totaled $62.4 billion, including a planned $56.1 billion inflow related to a mutual fund clearing services client.
Schwab had 8.18 million active brokerage accounts in the month, 765,000 banking accounts, and 1.45 million corporate retirement plan participants.
On Monday, Schwab rivals TD Ameritrade Holding Corp (AMTD.O), and E*Trade Financial (ETFC.O) reported month-over-month trading volume increases of 33 percent and 34 percent respectively. [ID:nS1E78B0R3]
Schwab completed the $1 billion deal to acquire optionsXpress on Sept. 1, expanding its offerings in the options and futures market. [ID:nN1E78014C]
The August metrics for optionsXpress were not included in Schwab's report for the month.
Separately, the company said average daily trades at optionsXpress were up 17 percent in August from July and up 44 percent a year earlier, to 55,000.
Client assets were down 4 percent from July, and up 13 percent from August 2010 at $8.1 billion, while new brokerage accounts were up 50 percent from both the previous month and the previous year, at 3,000.
OptionsXpress had 403,000 client accounts in the month, up 1 percent from July and 9 percent from August 2010. (Reporting by John McCrank in Toronto; editing by Rob Wilson)