BlackRock has slashed at least $20m from its investment research expenditure, heaping significant pressure on the asset management giant’s City broking clients that are already struggling to adapt to regulatory change.

The world’s largest investment company reduced its external research budget in Europe, the Middle East and Africa by almost 60% last year, to between $10m and $15m, according to people familiar with the cuts. Two senior executives at separate research providers say the asset manager’s cuts have, in fact, been far deeper and that the amount it spends on investment research has fallen from a much higher $100m.