Legal & General paid 2,614 group protection claims in 2017, worth a total of £284m and representing almost 18 per cent of the industry total.
The provider paid almost 100 per cent of group life claims in 2017.
A total of £206m was paid to all claimants, with the average claim payment worth more than £123,000.
Legal & General paid more than £9m in group critical illness claims in 2017, with an average claim payment of almost £62,000, and almost £51m of new group income protection claims in 2017, with a total of more than £68m of claims being paid to all claimants and an average claim payment of £23,380.
Mental health issues accounted for 29 per cent of new claims in 2017 and have been the top cause of claims on Legal & General’s group income protection policies since 1999.
Vanessa Sallows, benefits and governance director at Legal & General’s Group Protection, said: "These new figures clearly show the vital role that Legal & General plays within the group protection industry.
"Paying a total of £284m in 2017 highlights the valuable financial support these policies can provide to our customers and their employees when they need it most."