United Parcel Service Inc.’s union asked the company for major pay increases and better benefits as negotiations over its next five-year labor contract intensify.

The proposals, laid out in a 28-page document the union presented to the company on Wednesday, also include requests for increased pensions and protections for health-care coverage, along with the “big raises,” Sean O’Brien, president of the International Brotherhood of Teamsters, said in a webcast to Teamsters.

O’Brien didn’t provide more details, but said it was the largest economic package in US labor history.

Talks on the nationwide contract, which expires on July 31 and covers about 340,000 workers, are in their ninth week and so far have dealt mostly with non-economic issues — such as demands for air conditioning in delivery trucks.

UPS Chief Executive Officer Carol Tome has said she’s confident a deal will be done before the deadline. Without a deal, the Teamsters could go on strike as soon as Aug. 1.

UPS still believes it will reach an agreement by the end of next month “that is a win for our employees, the company and our customers, and the union,” a spokesman said in an emailed comment.