DALLAS -- Southwest Airlines ( LUV) says it has a tentative three-year contract agreement with the Transport Workers Union. The Dallas-based discount carrier announced the tentative deal Friday night. The agreement with workers in ramp operations and provisioning, plus freight agents, will be submitted to union members for approval. TWU Local 555 represents nearly 7,780 Southwest workers. Southwest Airlines says the new agreement would run through June 2011. The current contract began amendable on June 30, 2008. Contract talks began early last year.