Even though their wealth management revenue barely budged in 2015, banks and credit unions using third-party broker-dealers held on to one piece of very good news: their fee-based business was up a significant 17%.

This, of course, is a welcome development given the Labor Department's new fiduciary rule, which severely restricts advisers' ability to charge commissions for retirement-related advice.

Financial institutions that partner with third-party broker-dealers generated $367 million in advisory revenue, up from $315 million in 2014, according to the latest Kehrer Bielan TPM report. Revenue from the sales of investment products, in contrast, fell 2.4% to $1.4 billion with mutual funds and variable annuities suffering the greatest declines.

Overall, they generated $1.9 billion in investment services revenue, unchanged from 2014, according to Kehrer Bielan data.

TPM-affiliated banks and credit unions had yet another reason to be encouraged. They were able to post a 2.8% uptick in their adviser rolls, despite steep competition from wirehouses that offer large recruiting bonuses. Banks that own their broker-dealer, meanwhile, saw a slight .5% drop in their adviser headcount.

Financial institutions that work with TPMs were also better able to retain their advisers than bank-owned broker-dealers. "Advisor attrition in TPMs was less than half the attrition experienced in bank BDs," the authors Ken Kehrer and Tim Kehrer write in the report.

The report ranked TPMs on several fronts. Raymond James led the charge in adviser productivity. The average Raymond James adviser produced $387,755 in investment services revenue, beating Cetera Investment Services, its closest rival, by more than $55,000.

LPL Financial dominated market share, hogging 32.3% of revenue, 31.9% of advisers, and 27% of financial institutions.

Infinex Financial Group pummeled the competition in revenue growth. The firm's revenue grew 21.6%, most of it due to its acquisition of Essex National Securities.

The 2015/2016 Kehrer Bielan report surveyed the nation's eleven largest TPMs, which collectively work with 2,777 banks and credit unions. The survey has been conducted annually since 2006.