ATLANTA — Once again, speculation is building that Delta Air Lines and Northwest Airlines could announce their plans to merge–as soon as Tuesday–following another round of pilot talks from each carrier.

Atlanta-based Delta and its pilots met over the weekend to discuss a potential agreement that would give pilots a pay hike and a stake in the combined airline, according to today's Wall Street Journal. Northwest pilots met separately in Minnesota on Sunday reiterating the union's position that it will oppose a merger that does not have their interests at the forefront of the decision-making process.

The deal could value Northwest at roughly $3 billion, according to the publication, citing unnamed sources, though terms were still being negotiated. If Delta and Northwest proceed and the transaction receives regulatory approval, the combined carrier would be the largest in the world.