The pick-up in margin lending activity in the June quarter was not sustained in the September quarter, as a weaker equity market and an increase in margin calls tested investor appetite for geared share investing.According to the latest Reserve Bank margin lending figures, accounts balances fell from A$12.4 billion in the June quarter to $12.3 billion in the September quarter.The June quarter result was the best for the sector for three years but the momentum appears to have stalled. The S&P/ASX 200 equity benchmark fell 6.6 per cent during the September quarter.The number of margin loans accounts was unchanged at 144,000.The rate of margin calls rose from an average of 0.56 per 1000 clients per day in the June quarter to 0.88 per 1000 clients per day in the September quarter.