Marketing is suffering from an “acute succession crisis” as the proportion of external hires for the top CMO job soars.

According to data from executive search firm Russell Reynolds, 72% of appointments to top marketing jobs in the first half of the year were external hires, up from 64% this time last year. Technology and healthcare companies in particular are averse to hiring from within, with 89% and 82% of CMO appointments coming from external hires.

But professional services, industrial and natural resources, and the apparel and retail sectors have experienced some of the biggest increases in external appointments.

“Top marketers continue to be hired for, as opposed to being promoted into, the most senior marketing leadership roles in a company,” says the report. “There is a clear succession problem for CMOs as just one in four marketing leadership changes was someone from within their respective company.”

CMOs are also failing to get promoted in their own organisations. Just 21% were internally promoted, and only 25% of those took on a more senior role outside marketing such as CEO, president or general manager. Some 34% took on a ‘new’ marketing role such as chief brand or customer officer.

Marketing leaders are also having to wait longer for an internal promotion. The average tenure with a company before promotion was 7.3 years, up from 6.3 years in the final two quarters of 2016 although down from the 9.9 years seen in the first half of last year.

Top marketers continue to be hired for, as opposed to being promoted into, the most senior marketing leadership roles in a company.

Among the 47% that left to ‘pursue a new opportunity’ still only 22% were able to make the jump to a more general leadership role with responsibility for profit and loss.

“There is concern that there is not much promise for CMOs to move up within their own organisation. Even moving up by joining another organisation only occurred one in five times,” the report explains.

Both factors are part of the reason why record CMO turnover continues to rise. According to the data, there were 187 marketing leader appointments in the first half, the highest number since Russell Reynolds began tracking appointments five years ago. There was also a decline in gender parity, with 41% of appointments women, down from 47% in the first half of last year.