UPDATE 2-Window for London FX 'fixing' to widen after trading row
* State Street unit WM announces move in memo to banks
* Implements global regulator FSB's reform recommendations
* Trading could become exchange-based: head of industry body (Recasts with comment from industry body, more context)
By Patrick Graham
LONDON, Nov 17 (Reuters) - London's benchmark foreign exchange "fixings" will move to a five-minute calculation window, from one minute currently, as of 2200 GMT on Sunday, Dec. 14, the WM Company said in a memo sent to banks on Monday.
The move by WM, a unit of State Street Corp, follows the levying of the first fines on banks in a row over alleged manipulation of foreign exchange markets and the fixings, used to set reference values for thousands of contracts worldwide.
After a torrid week for the biggest and least regulated of the world's major financial markets, worth more than $5 trillion a day, the head of the industry body ACI Financial Markets also gave a nod towards the potential for moving more trading onto regulated exchanges.
The widening of the window is the first clear sign that recommendations made in September by the global regulators of the Financial Stability Board for changes to the fixings are being implemented.
Other proposals, agreed after consultations with banks, asset managers and other stakeholders, include changes to trading floors that will keep client orders to be executed at the fixing rate separate from spot trading desks. Continued...