This will make the NSE the first stock exchange to launch ALBM-based trading in rolling mode ahead of the BSE, which is also planning to launch CRS in modified carry forward mode in the last week of November. The BSE had scored over the NSE by launching futures trading on June 9, three days ahead of the latter.

``Trading in ALBM-based rolling settlement system will be commenced within 10 to 15 days. We may not require more time than that as the mock exercises were are getting over,'' NSE deputy managing director Ravi Narain told The Financial Express here on Tuesday.

The trading would commence in the 15 stocks specified by Sebi after the Risk Management Committee meeting in the second week of last month, Mr Narain said, but added that the exchange was yet to decide the specific date for the launch.

The NSE was scheduled to launch trading in the 15 stocks under Continuous Net Settlement (CNS) system by December-end, and if allowed by the regulator, it would also be ready to commence trading in index-based options too in the same month, Mr Narain said. ``I am giving the broad dates, so that we will be in a position to start CNS much before this date,'' he added.Sebi's risk management committee has decided to put in abeyance commencement of the modified carry-forward, ALBM and/or CNS-based trading in CRS and brought 15 `B1' group stocks, which were already being traded under CRS, on an experimental basis under these modes.

Advancing the date of launch of trading under the system by the NSE brings the question as to who between the leading exchanges - the NSE and the BSE - would be first to launch trading in this mode, for which the Sebi had not set any date. It had asked the exchanges to do so whenever they were ready with the necessary software, after the risk management committee meeting.

BSE president Anand Rathi said on Monday that the exchange would kick off CRS under modified carry-forward (MCF) mode anytime after the third week of this month and trading under CNS would be launched next month.

The BSE has been conducting mock trading in five stocks under MCF-based rolling settlement since October 30. Since the beginning, the NSE was averse to MCF, stating that it was an archaic system, while the BSE calls ALBM an MCF with a different name. However, Sebi had brought both the modes on par by deciding to treat them equally for calculating margins.