REUTERS — The number of years it takes to become partner at a major law firm is getting longer and longer, new research shows, despite tentative moves by some large firms to speed the way. Associates last year took an average of nearly nine years to make partner at the firms where they began their careers, according to legal industry consultancy Leopard Solutions, which tracked both equity and nonequity partnership promotions at about 1,000 U.S. law firms. Its survey, released Thursday, showed the time it takes for entry-level associates to become partners at their firms reached 3,185 days on average last year, an increase of 136% from when it began tracking the data in 2012. Lawyers who swap firms as associates are also treading a longer path to partnership than they once were. The time it takes lateral associates to make partner has increased by more than 61% over the last nine years to 1,550 days, according to the report.