By Simon Jessop LONDON (Reuters) – British asset manager abrdn will take a tougher line at annual meetings of U.S. companies that have poor levels of ethnic and gender diversity on their boards of directors, it said on Monday. Abrdn, which manages around 465 billion pounds ($608 billion), said it would vote against the nomination committee chairs at any S&P 1500 or Russell 3000 company that does not have at least one racially or ethnically diverse board member. In addition, abrdn said it would expect women to make up at least 25% of the board at all large-cap companies, rising to 30% in 2023. …