The percentage of investment advisory firms with written social media policies has nearly doubled in the last three years, according to a new study.

Written social media guidelines are on the books at 83 percent of firms this year compared to 80 percent in 2012 and 43 percent in 2010, according to the eighth annual Investment Management Compliance Testing Survey released Friday from the Investment Adviser Association, the ACA Compliance Group and the Old Mutual Asset Management.

The percentage of advisory firms allowing workers to use their personal Facebook, Twitter and LinkedIn sites for business nudged into the majority, at 51 percent in 2013 after staying at 46 percent the previous two years.

At the same time, the tension over social media in the industry has declined, with 25 percent of respondents referring to it as a “hot compliance topic” compared with 43 percent in 2012.

Advertising and marketing were ranked higher as compliance concerns, with 34 percent in 2013 compared with 26 percent in 2012. Custody also became a greater concern, with 20 percent this year compared with 12 percent a year earlier.