Paul Remington vice chair of the East of England Ambulance trust thanks Ms Ball for her hard work.
He said: “Maria spent many years leading the ambulance service and I would like to thank her for her dedication and commitment through what have been some challenging times.
"Maria oversaw the formation of this Trust, bringing together three disparate organisations into one service, and its subsequent development."
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November 2015 could heading for the record books as the warmest on record in East Anglia.
Showers will largely die away this evening and winds will decrease. Feeling chilly with clear spells. Lows of 3 deg C.
This afternoon will see squally showers- these will be occasionally heavy. Becoming very windy later with gales.