UPDATE 1-E*Trade Jan. trading volume off 20 pct from year-ago

* Client trades down 20 pct from last year, up 20 pct from Dec

* Assets in brokerage accounts up $700 million

* Analyst says metrics better than expected

* Shares up 0.87 pct on Monday morning

Feb 13 (Reuters) - Online broker E*Trade Financial Corp said on Monday its trading volume fell 20 percent from a year earlier, but rose 20 percent from December, when many investors moved to the sidelines due to uncertainty in the markets.

E*Trade's clients made an average of 145,390 daily revenue trades - a widely watched industry measure - in January.

New York-based E*Trade also said it added 10,041 net new brokerage accounts in the month. Client assets in brokerage accounts increased by $700 million, compared with rises of $1.2 billion a year earlier and $500 million in December.

JMP analyst David Trone said the trading numbers were better than he had expected and noted that the 8 percent month-over-month rise in client brokerage assets was better than the 4 percent increase in the Standard & Poor's 500 in the month.

Share of E*Trade were up 0.97 percent at $9.29 on Monday morning.

Total customer assets were $185.4 billion, up 2.3 percent from a year earlier.

Rival brokerage TD Ameritrade said on Wednesday that its trading volume was down 17 percent in January from a year earlier at an average of 374,000 trades per day. That was up 18 percent from December.