(CNN) -- More than 60 union workers for the company that provides bus service in Phoenix were locked out of their jobs Monday as contract negotiations failed to reach an agreement.
A spokesman for Teamsters Local 104 confirmed Veolia Transportation locked workers at 12:01 a.m., as it said it would do in a news release Sunday. It said it the lockout would be in place "pending a contract agreement."
The union will file charges with the National Labor Relations Board on Monday and may put up a picket line, said Teamsters union representative Andy Marshall
A lockout was the company's "only alternative" after a series of contract extensions, Valerie Michael, director of corporate communications for Veolia Transportation, said in a written statement. The lockout was put in place as the fourth contract extension expired.
"The union is determined to delay any resolution," she said.
Marshall told CNN affiliate KPHO that he found out about the lockout Sunday evening when transportation officials handed him a notification after weekend negotiations ended.
The sticking point in the talks is job security, he said. Veolia wants a contract clause that states the company can outsource jobs at any time without the union's input, according to Teamster officials.
Teamster's Local 104 has 62 members out of work at this time, but Marshall said there are several hundred other union workers currently working without a contract who may be put out of work in the coming days.
There was no word immediate word on how the lockout will affect bus service in Phoenix.