Petrus Advisers | 3,502 followers on LinkedIn. Petrus Advisers is a London based investment manager | At Petrus Advisers our strategy is focused on developing a deep, fundamental understanding of the public companies we invest in, paired with active engagement both publicly and behind-the-scenes. We focus exclusively on European countries where we can invest like “locals” and industries within which we are experts. Petrus Advisers is committed to a responsible investment approach and to upholding high professional standards.