Regional carrier Republic Airways Holdings Inc., which warned over the summer that it could be forced to file for bankruptcy-court protection if it couldn’t solve its pressing pilot hiring and retention challenges, said Tuesday that a majority of its 2,100 aviators approved a new three-year labor contract that significantly raises pay and improves work rules, the Wall Street Journal reported yesterday. The pact, which will go into effect in a few days, will succeed the current contract, which hadn’t been updated in eight years. The new deal lifts starting first-officer pay to $40 an hour, raises pay for other first officers and boosts captain pay. Indianapolis-based Republic said it would invest about $50 million a year over the three-year duration of the new contract, including signing bonuses and anniversary bonuses.