Henderson is to change the investment policy of Matthew Beesley's International fund as well as renaming the vehicle to reflect its more concentrated investment approach.
As of 2 December, the fund will be renamed the Henderson World Select fund while its investment policy will formally commit it to a typical portfolio of between 30-40 holdings.
The £60m fund, run by head of global equities Beesley (pictured) since May 2012, has seen its number of holdings steadily reduce since 2008.
In a letter to advisers, Henderson head of UK retail Simon Hillenbrand said the increasingly concentrated portfolio had not led to an increase in the fund's risk profile.
"A concentrated portfolio can also increase risk in the portfolio. In practice, however, we have not seen an increase in the risk profile of the fund against its index.
"The volatility of the fund has been similar to the volatility in the broader equity market (as represented by the MSCI World index)."
Research produced for Investment Week last year suggested concentrated portfolios had actually outperformed in the volatile markets of recent years.
The Henderson International fund has returned 21.5% in the year to 30 August, according to Morningstar, compared with an IMA Global sector average return of 19.4%.
The new name will more accurately reflect the global including UK remit of the portfolio, the group added.
Slow progress in improving diversity
Share purchase deal with assets of £28m
Came into effect in January
Three examples of compensation rule issues
Buying in baskets