Leighton O’Connor has been named the Haverhill School Department’s interim business manager. O’Connor, who retired in 2008 as business manager for the Gorham School District in Maine, has served as a budget consultant for the Haverhill schools for the last three years. The School Committee voted unanimously on June 6 to offer the position to O’Connor. His contract will be for one year. Kara Kosmes, Haverhill’s longtime assistant superintendent for finance and operations, is leaving the district July 1 for a similar position at Whittier Regional Technical High School.