SEATTLE — The international president of the Machinists union says Boeing’s revised contract offer is an improvement of more than $1 billion.

In a letter to union members, Tom Buffenbarger said the offer workers will consider next week is a significant improvement over a contract the union rejected last month.

Boeing Co. seeks a new contract with Machinists in the Puget Sound area that would move workers away from traditional pensions. In the revised offer, Boeing has backed away from a plan to slow the rate at which employees rise up the pay scale. The company is also offering $5,000 in additional bonus money and improved dental coverage. Boeing has vowed to build the company’s new 777X airplane in the Puget Sound if the Machinists agree to the pact.

First Published December 28, 2013, 5:00 a.m.