July 22 (Reuters) - Boeing ( BA ) sent a contract offer

on Tuesday to union members who assemble its fighter jets in the

St. Louis area.

The company's proposal includes a 20% general wage increase

over four years and a $5,000 ratification bonus, as well as more

vacation time and sick leave.

Local union leaders are recommending that the more than

3,200 members of the International Association of Machinists and

Aerospace Workers District 837 approve the contract when they

vote on Sunday, the day it expires.

Boeing's ( BA ) defense division is expanding manufacturing

facilities in the St. Louis area for the new U.S. Air Force

fighter, the F-47, after it won the contract earlier this year.

The company is expected to expand its workforce in the

coming years, as well.