A tentative date of Dec. 21 has been set for an exchange of contract proposals between the management group representing 26 trucking companies and the Teamsters union.

Trucking Management Inc. represents some 110,000 drivers and dockworkers nationwide and includes some of the nation's trucking giants, including CF Motor Freight, Yellow Freight System and Roadway Express.The meeting is the first in what is expected to be a lengthy series of Washington, D.C., talks to replace the existing three-year contract that will expire on April 1, 1994.

While the union has yet to reach an agreement on supplemental contracts with its largest employer, United Parcel Service Inc., the Teamsters freight division is laying the groundwork for the other major contract covering drivers - the National Master Freight Agreement (NMFA).

On Dec. 16, representatives from some 700 locals nationwide will meet in Washington to approve proposals for the contract, many gleaned from a membership survey showing that members valued job security as a key issue. A negotiating committee also will be appointed.

Four truck company signatories to the freight agreement failed in the last year, and several are financially shaky, heightening members' concerns about their future.

Labor also is expected to focus on the growth of intermodal operations and non-union trucking companies owned by NMFA signatories. Management, in turn, will seek labor's support for work-rule changes to allow them to better compete against growing non-union trucking companies.

"If we can't hold the line, there just won't be any organized sector. They'll hammer us out," said an official with one union trucking company familiar with the freight talks.

In the UPS talks, ballots for three of the six regional supplements that failed to pass will be mailed out this week, a Teamsters spokesman said. While the national contract covering 165,000 workers passed by a 2-to-1 margin two weeks ago, the failure of the regional supplements prevented the national contract from taking effect.

Some members complained that in at least two instances, the regional supplements that failed to pass will be sent out virtually unchanged for a second vote.

"It's clearly a fast shuffle," said R.V. Durham, head of the 2,500-UPS worker Local 391 and longtime critic of the Teamsters international. "I think the members deserve more than that."

Mr. Durham made an unsuccessful run for the Teamsters presidency in the union's last election.

The contract supplements failed in New Jersey, Central and Western Pennsylvania, Puerto Rico and the Atlantic area, which covers Baltimore to South Carolina.

"Members are being given another opportunity to review the supplements," said Bernie Mulligan, a Teamsters spokesman.