Capital Group, a Los Angeles-based global investment manager which shuns publicity, has more than doubled its stake in Finmeccanica, the Italian defence and aeronautics group, to become the largest non-state shareholder.

Finmeccanica said on Tuesday it had been informed by Consob, the Italian stock market regulator, that Capital Research and Management, part of the Capital Group, had increased its stake to more than 5 per cent from 2.1 per cent.