BlackRock Inc., the world’s biggest money manager, is accused in a lawsuit by two pension funds of reaping “grossly excessive” compensation from securities-lending returns associated with iShares Inc., Bloomberg News reported yesterday. “Defendants have systematically violated their fiduciary duties, setting up an excessive fee structure designed to loot securities lending returns properly due to iShares investors,” representatives of the funds, which invest in iShares, said in a complaint in federal court in Nashville, Tenn. The pension funds allege that BlackRock affiliates collected 40 percent of revenue earned from securities lending transactions as compensation. Blackrock said that the suit is without merit and will contest it.