Researchers reviewed women's representation in about 24,000 positions in firms on Britain's blue-chip FTSE 100, mid-cap FTSE 250 and FTSE 350 indices.
This puts Britain in second place globally, up from fifth in 2020 and just behind France which has a nearly 44% representation, according to the report.
Homebuilder Taylor Wimpey this month named Jennie Daly as CEO and Britain's largest pet supplies retailer, Pets At Home, appointed Sky UK executive Lyssa McGowan as its CEO.
The review also set out four new recommendations, including increasing the minimum board and leadership representation of women in FTSE 350 companies to 40% by the end of 2025.
In July, Britain's financial regulator also said at least 40% of board members in blue-chip companies should be women.
The latest report also found that female board representation in 2021 in the FTSE 250 and FTSE 350 grew by roughly 37% and 38% respectively.
British business secretary Kwasi Kwarteng lauded the progress, but said there was still more work to be done, with many companies yet to hit a 33% target set by previous reviews.
"Only one in three leadership roles and around 25% of all Executive Committee roles are held by women and there are very few women in the CEO role," Kwarteng in a statement.
The report also said that number of women in chair roles across the FTSE 350 rose to 48 in 2021 from 39 a year earlier.
Water utilities Severn Trent and Pennon, and Holiday Inn owner IHG are three of the companies with women in chair roles.
(Reporting by Sinchita Mitra in Bengaluru; Editing by Nick Macfie)