Morningstar has awarded Lazard Asset Management its top rating in its Isa league table with 4.14 stars out of five.
St James’s Place came second with an average of 3.91 stars. Artemis, Framlington and Mellon completed the top five.
Neptune Investment Management was the most improved fund group, rising 22 spots to sixth place. It had an Isa rating of 3.80, up from 3.20 in the previous table.