Standard & Poor's has altered the ratings on five global equities portfolios, with funds from Gartmore, M&G, Jupiter, JO Hambro Investment Management and Axa all affected.
The Johim Global fund is the only one to have been downgraded, from AA to A, with S&P citing Stuart Mitchell's departure as manager as the main reason for the downgrade.
Despite finding Alex Pritchard, who has taken over the portfolio, to be an able stockpicker, the ratings agency said it is yet to be seen how this will benefit the fund.
Gartmore Global Focus has been upgraded from AA to AAA because S&P is confident in manager Neil Rogan's aggressive investment approach.
It said Rogan shows considerable skill in mixing longer-term strategic investments with shorter-term tactical plays, with turnover on the vehicle usually over 400%.
Axa Global Growth has gone from being non-classified to AA rated because it is managed identically to the group's AA-rated Global Equity Alpha fund.
M&G Global Leaders and Jupiter Global Managed, both also previously non-classified, have received A ratings.
In the case of the former, S&P said the rating was given because manager Aled Smith runs the fund with flair and is supported by an experienced team head.
While the Jupiter portfolio is managed by John Chatfeild-Roberts, whose Merlin fund is AA-rated, it received the lower grade because S&P felt the fund manager had less experience with this particular kind of product.
Two global vehicles
'Further plug advice gap'
Must appoint separate CEOs and boards
Advisers do come out well
Will report to Mark Till