``We are of the view that Inter-connected Stock Exchange and regional stock exchanges should have a uniform settlement system,'' Sebi chairman D R Mehta said.

He said Inter-connected Stock Exchange had also accepted the uniform trading cycle but changed their stance later. ISE is expected to give a presentation this week to Sebi on the need to have a seperate trading cycle.

The Inter-connected Stock Exchange , the proposed stock exchanges by more than 12 regional stock exchanges, is banking on a different trading cycle to generate arbitrage volumes arising from share price differences in ISE and regional stock exchange.

``ISE members can do arbitrage business with the National Stock Exchange, Bombay Stock Exchange or Delhi Stock Exchnage ,'' Mehta said adding thatarbitrage trading by ISE with regional exchanges (who are also members of ISE) could pose problems in stock exchange surveillance.