Boeing Co. on Tuesday presented what it called its final contract offer to more than 18,000 machinists, offering the union members a 10 percent increase in pension payouts but otherwise changing little from its last previous offer.

“We heard what the union was saying about pensions,” Boeing spokesman Charles Bickers said.

The Seattle-based Machinists Lodge 751, which represents workers who assemble commercial airplanes, said in a statement that it had received the three-year offer and was analyzing it before responding.