Butcher joins Jeff Taylor, head of European equities, who has managed the fund since 2001.
Over the last five years it has returned 32.7% versus an Equity Europe peer group average of 33.2%.
Invesco said the move was part of a drive to ensure it had at least one manager able to deputise on each of its mandates.
Taylor (pictured below) said: 'Stephanie and I have worked together for 15 years, over which time the wider team has developed a shared investment philosophy.
'Stephanie’s broad contribution to the team along with her investment insight and expertise has ensured a diversity and depth of thought which further strengthens our investment proposition.'
Butcher has more than a quarter of a century's worth of experience in the financial industry. Overall, she manages over £3 billion spanning European equity, income and absolute return portfolios.
Before joining Invesco she worked at Aberdeen Asset Management, where she worked as a retail fund manager on the European equities desk and as a US portfolio manager.