Legal & General paid 96% of all group protection claims in 2015, worth a total of £266m - representing almost a fifth (18.88%) of the industry total of £1.4bn.
Legal & General's data showed the insurer paid 99.9% of group life claims in 2015, an increase on 2014's figure of 99.6%.
The insurer also paid 92% of group income protection claims last year, worth £45m, which is an increase on 2014 and also higher than the industry average of 84%.
The insurer is releasing its figures following Group Risk Development (GRiD) recently publishing its figures from 2015 showing the total payments made by the industry last year.
Some 595 people in 2015 returned to work using L&G's early intervention support within the deferred period , almost one third of the 1,878 total reported by GRiD.
Martin Noone, managing director, Legal & General Workplace Health and Protection, said: "GRiD's annual figures are a very useful analysis of the value provided by the group protection industry each year, they also highlight Legal & General's role within the industry.
"To see that in 2015 we paid nearly a fifth of total industry claims made in the UK is pleasing, so too are the increased proportion of group life claims we paid and the above average proportion of our Group Income Protection claims paid.
"What is most important is being able to evidence our proposition to our customers. Our active intervention and funding rehabilitation support where appropriate enabled 595 people return to work before their case became a claim, a near 40% increase on 2014.
"This represents almost a third of the industry total reported by GRiD and emphasises the many ways we can support both employers and individuals during what can be an extremely difficult period."
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