The phrase "a decreasing likelihood" is correct and usable in written English.
It can be used when discussing the probability of an event happening over time or under certain conditions.
Example: "As the project progresses, there is a decreasing likelihood of meeting the original deadline."
Alternatives: "a diminishing chance" or "a reduced probability."
Environmental groups expressed concern that the successive financial losses, as well as a decreasing likelihood that the 3 Deeps mine will go ahead amid falling uranium prices since the Fukushima disaster, mean the company will not be able to pay for the full clean-up.
A χ test for trend confirmed a decreasing likelihood of herbal medicine use with increasing deprivation (X=4.13; P=0.042).
As already described, basic life support saves the 'best' cardiac arrest patients; any subsequent advanced cardiac life support intervention has a decreasing likelihood to restore spontaneous circulation over time.
The report warns of weight problems spiralling out of control as "people who are overweight or obese were seen to be stigmatised and this was associated with a decreased likelihood of engaging in healthy behaviour such as exercise".
The recipiency rate change from 2007 to 2010 is thus a combination of a decreased likelihood of exhausting benefits and an increased propensity to receive benefits early in the unemployment spell.
Conversely, higher levels of friendliness and vigor predicted a decreased likelihood of next-day friend conflict.
Overcrowding appears to be associated with a decreased likelihood of timely treatment for acute AMI in our ED.
A reliance on stereotypes, combined with a decreased likelihood of updating one's opinion in the face of new evidence, can create an environment where employees, and particularly those from stereotyped groups, are unfairly and inaccurately evaluated.
In the Americas, Africa, and Indian Sub-Continent, the increased risk index was actually associated with a decreased likelihood of an unsuccessful attack.
Weapons present (Exp[B] = 0.22) and number of pirates (Exp[B] = 0.97) were associated with a decreased likelihood of an unsuccessful attack.
