Union leaders representing city bus drivers and the management of Metropolitan Transit District (MTD) have agreed to work together to lobby the Department of Labor to release $2.3 million in federal funds that have been frozen because of a labor-management dispute at MTD. Thus far, no date has been set for the conference call, but without the funds serious service cuts are imminent. The money was frozen after Teamsters Local 186, which represents MTD drivers, objected to its release last month, citing new contract language requiring newly hired drivers pay an unspecified — but possibly quite large — portion of their retirement out of pocket. The Teamsters have opposed this requirement, arguing such contract changes should be negotiated at the bargaining table. MTD officials have insisted the new language is required by California’s Pension Reform Act, passed by the State Legislature last year. Next week, the MTD board will hear a report detailing what services would have to be cut and by how much should the dispute not be resolved.