19June200909:45

Service Announcement 001/190609

Amendments to segments, sectors and period rules and addition of price format codes

The purpose of this announcement is to inform customers of the following changes:

-Changes to 2 ITBB segment descriptions and 19 ITBB sector names.

-6 existing ITBB sectors and 3 existing IOB sectors will be deleted.

-4 IOB sectors previously made redundant will be deleted.

-Addition of 1 new period rule.

-Change to the closing price calculationfor ITBB.

-Addition of new price format codes.

Amendments to segments, sectors and period rules

ITBB segment/sector changes and IOB sector changes are detailed in full in Appendix 1. No securities will be migrated as a result of the scheduled sector deletions.

New period rule ‘IBC2’ will be introduced to the sector default schedule at 15:20 for all ITBB sectors with price monitoring controls (IBHL, IBLL, IEUL, JEUL, JPL1, INEH, INEL, JNEH, JNEL, IEUH). If price monitoring controls are activated during this period then the security will move immediately into the closing auction. This change will bring the ITBB into line with the Exchange’s other trading services.

New period rule / Description
IBC2 / INT.BB.EQ ODR.TRDG.2

The closing price calculation for all ITBB segments will continue to be determined by the uncrossing price in the closing auction. In the event that an uncrossing does not occur the closing price will now represent the price of the last automated trade in that security (UT/last AT).

Addition of new price format codes

The following price format codes will be made available on TradElect:

New price format code / Description
P / FIVE
C / TEN
G / FIFTY

The following price format codes currently on TradElect will be made available to the London markets:

Price Format Code / Description
M / ONE THOUSANDTH
Y / ONE TWO-THOUSANDTH

Schedule for introduction of changes

The Customer Development Service (CDS) will be updated with these changes on Monday 13 July 2009.

TradElect Production (LIVE) will be updated with these changes on Monday 20 July 2009.

Administration

Customers are advised to take either the Reference Data Changes service for CDS on Friday 10 July 2009 or to take the Full Reference Data Download CDS Service Channels on Monday 13 July 2009.

TradElect Production customers are advised to subscribe to the Reference Data Changes on Friday 17 July 2009 or the Full Reference Data Download Service on Monday 20 July 2009.

The TradElect Parameters document will be updated immediately before the above changes are implemented and it can be accessed as a download from the following link:

London Stock Exchange Group plc. Registered in EnglandWales No 2075721