Home Retail, C&WW, Invensys set to exit FTSE 100

* Invensys, Home Retail, Cable & Wireless set to exit

* Resolution, Tomkins, Weir Group on track to enter

* SSL or Informa set to enter if committee excludes Tomkins

LONDON, Sep 3 (Reuters) - Invensys (ISYS.L), Home Retail Group (HOME.L) and Cable & Wireless Worldwide (CWP.L) are set to drop out of Britain's FTSE 100 .FTSE index after a quarterly rejig, data showed on Friday.

These companies look set to be replaced in the UK blue-chip index by insurance buyout group Resolution (RSL.L), car parts maker Tomkins TOMK.L and pump manufacturer Weir Group (WEIR.L).

Tough economic conditions brought about by the global financial crisis and government austerity measures have hit the share prices of those exiting the index.

Engineer Invensys lost ground in July after it cut its 2011 forecasts as the firm's rail division expenditure came in higher than forecast.

Shares in Cable & Wireless Worldwide (CWP.L) slid in July after the telecoms firm warned that trading was hit by a significant slowdown in UK public sector spending.

And Home Retail Group (HOME.L) was hit in June after the household goods retailer posted a bigger than expected drop in quarterly sales at its Argos stores, as cash-strapped, low income shoppers cut back on spending.

Companies outside the FTSE 100 that grow in market value to rank among the 90 largest are automatically promoted, while the FTSE 100 firms with the lowest value or that fall to 111th spot or below drop into the FTSE Midcap 250 index .FTMC.

Moving to the companies entering the top flight, Resolution swung back to a half-year profit, it announced in August, lifted by its takeover of AXA's UK life insurance unit.

However, industrial group Tomkins' entry into the index is open to doubt as it has agreed to be acquired by Canadian investors Onex Corp (OCX.TO) and the Canada Pension Plan Investment Board for 2.9 billion pounds in a deal which should be completed by Sept 24.

A FTSE committee will look at factors other than market capitalisation that should be taken into account when deciding whether a company should move into the index and will decide whether Tomkins will move in, a spokeswoman at the index group said.

Condom maker SSL International SSL.L is the next biggest company in line for promotion but it is being bought by Reckitt Benckiser (RB.L) in a deal due for completion in the fourth quarter.

The biggest company after SSL is business information provider Informa (INF.L).

Index compiler FTSE will formally announce the changes to the FTSE UK index series after the market close next Wednesday.

The review uses the closing prices from next Tuesday but the changes have to be confirmed by a FTSE committee on Wednesday.

The index changes will be implemented after the market closes on Sept 17. (Reporting by Simon Falush; Editing by Greg Mahlich)