The managers of the Baillie Gifford Japanese fund were ranked 99th among the 1601 managers rated by financial publisher Citywire across 35 countries when the latest investment performance figures for the three years to March 31 were compiled. They were 69th in the previous month.
This is the second consecutive month the pair have topped the rankings for fund managers working for institutions with a strong Scottish presence. However, Ms Whitley and Mr Brett, both AAA rated by Citywire, previously headed the Scottish table for five consecutive months during 2013.
The Herald-Citywire survey measures risk adjusted performance against relevant benchmarks. Ms Whitley's and Mr Brett's continued success ensured that Baillie Gifford retained 22 Citywire rated managers.
However, the number of managers working for houses with a significant Scottish presence who qualified for a rating, which denotes strong performance, fell from 114 to 99 during the month.
Standard Life Investments saw its number of rated managers fall from 17 to 14. Among those to lose a rating were Karen Robertson, manager of the Standard Life Investments UK Equity High Income fund and its head of global equities Mikhail Zverev who runs global equity portfolios on the grounds that their performance had dropped.
Two managers at Franklin Templeton lost their ratings taking their numbers to 12 as Marco Freire was deemed to no longer be a manager on the Templeton Emerging Markets Bond Fund and its chief investment officer for Asian equities Sukumar Rajah was deemed to no longer be eligible.
Artemis now has nine rated managers after Alexander Illingworth and Simon Edelsten, hired to establish a global equities mandate, were deemed to have insufficiently strong performance.
However, other Artemis managers are prospering. Tim Steer, manager of Artemis UK Growth, secured third spot in the Scottish table, as he leapfrogged Kames Capital's Audrey Ryan, to jump from fourth place in the previous month.
The former staffer at New Star Asset Management, which nearly collapsed during the credit crunch, is ranked 112th, up from 157th the previous month.
Ms Ryan is manager of the Kames UK Opportunities, Kames Ethical Equity, and Kames Ethical Cautious Managed funds. Her place in all Citywire rated managers fell from 93rd to 119th
Mr Steer's colleague Jacob de Tusch-Lec, manager of Artemis Global Income and Artemis Monthly Distribution funds, remained in fifth spot in the Scottish table.
He slipped one place in the overall rankings to 122nd. The only Scottish manager to gain a Citywire rating during the month was Aberdeen Asset Management's Asian chief Hugh Young.