Rather than hire a new executive director now, the Pittsburgh Water and Sewer Authority board has decided to bring in a management firm to oversee daily operations for as long as 18 months.

The board voted Friday to invite firms to compete for the work. Councilman Patrick Dowd, a board member, said the request for proposals should be completed by the end of the month.

In addition to daily management, the firm will provide guidance for the agency’s long-term future. That will include reviewing the agency’s use of engineering consultants and determining “where we stand in relation to best practices as a water and sewer authority,” said city finance director Scott Kunka, an authority board member.

Michael Kenney, the last executive director, quit in December 2010 amid questions about ties to a vendor providing a line warranty service to authority customers.

Two senior administrators, Tom Palmosina and Stephen Simcic, have shared management duties in the period that’s followed — a period that has seen a judge rule the line warranty program illegal and the agency’s stormwater management practices criticized after the deaths of four people in a flash flood in August.

In recent months, Mr. Dowd has criticized his colleagues for dragging out the decision on how to replace Mr. Kenney.

Mr. Kunka and state Rep. Dan. Deasy, D-Westwood, the authority chairman, said it was in the authority’s best interest to move carefully, not quickly.

In 2009, Resource Development and Management Inc., a firm under which Mr. Kenney once worked, issued a report critical of authority operations.

The board re-elected Mr. Deasy chairman and Robert Jablonowski vice chairman.