Axa Rosenberg, a quantitative asset manager that last year found a "coding error" that it delayed announcing until it was fixed, has seen its assets under management halve to €24bn after client withdrawals in the nine months to September.

Axa, the French insurer that owns Axa Rosenberg, said this morning that its subsidiary had suffered net outflows of €26bn in the first three quarters. Axa Rosenberg's website said its assets under management at the end of September were $33bn, or €24bn; the total at the start of the year had been €50bn.