Chicago—The average tenure for chief marketing officers among the top 100 advertised brands rose to 45 months last year, a two-month gain over the 2011 average, according to the ninth annual CMO tenure study from executive search consultancy Spencer Stuart.

The average tenure is now nearly double what it was in 2006, when it slipped below two years, to 23.2 months, the lowest tenure since Spencer Stuart initiated the study in 2004.

Among business verticals, the study found tenure is longest in industrial companies, averaging more than nine years (111 months), and shortest in the healthcare, automotive, restaurant and communications/media sectors, averaging between 28 and 32 months. CMOs of top technology companies had an average tenure of five years (60 months) last year, while chief marketers at leading financial services companies averaged four and a half years (54 months).