Delegates at a major labor group's constitutional convention have rejected a move to settle their differences with a rival union.

In a vote yesterday at the Sheraton Chicago Hotel & Towers, leaders of Unite Here knocked down a resolution to arbitrate with Workers United, an affiliate of the Service Employees International Union.

Unite Here formed in 2004 with the merger of the Union of Needletrades, Industrial and Textile Employees and the Hotel Employees and Restaurant Employees International Union, and it represents about 400,000 workers. The union has been bitterly at odds with Workers United.

Quarrels between Unite Here's leaders led to last month's departure of General President Bruce Raynor, the former U.N.I.T.E. leader who joined Workers United, an affiliate of the 2-million-member SEIU. The affiliate has also signed up thousands of former Unite Here members.

Unite Here, now run by former H.E.R.E. leader John Wilhelm, opened its national convention in Chicago yesterday.

Raynor, Workers United President Edgar Romney and SEIU President Andy Stern sent Unite Here President John Wilhelm an open letter earlier this month, asking that he submit to mediation.

Wilhelm has repeatedly turned down such requests, accusing Workers United of trying to steal Unite Here's members.

"This binding arbitration is simply a pretext to raiding us more," Wilhelm said at the convention yesterday. He called Unite Here Local 2552, whose delegates introduced the resolution, "a fictitious organization" created by Stern to undermine Unite Here's solidarity.

Local 2552 President Kurt Edelman, whose group represents laundry workers, food-service workers and facilities-services workers from across the United States, said the vote would have ended a "wasteful, destructive and unnecessary fight."

"Thousands of workers throughout North America are being hurt by this disastrous conflict, as their employers refuse to bargain new contracts, process grievances and allow basic union representation," Edelman said in a statement.

The vote came hours after Unite Here unveiled a pledge from 15 presidents of major labor unions to stand with the union. Among the pledgers were Randi Weingarten, president of the American Federation of Teachers, and Joseph T. Hansen, international president of the United Food and Commercial Workers International Union, who served as a mediator between Unite Here and Workers United.

The pledge commits supporters to "both materially and morally" oppose a raid by any union against Unite Here. It also urges an amicable, quick settlement of the conflict with Workers United.

Unite Here's convention ends tomorrow.