Selectmen on Monday unanimously chose the firm of Anderson & Kreiger LLP of Cambridge as town counsel. Attorney Arthur Kreiger had served as interim counsel since May, following the town’s dismissal of Robert Troy. The town will pay Kreiger a flat rate of $8,000 per month for non-litigation matters, and an hourly rate otherwise. Selectmen said they were pleased with the number of longstanding cases Kreiger settled for the town as interim counsel. A search committee received 13 applications and conducted seven interviews in public meetings before narrowing the search to three finalists.