Coutts & Company received by far the most complaints for decumulation and pensions per 1,000 policies sold between January and June this year, according to FCA data.
In the intermediation category, which includes brokers and advisers, the private bank and wealth management firm reported 67.8 complaints per 1,000 policies sold in the first half of 2019. Some 75% of these were upheld, the data revealed.
Second place went to Barclays Bank with 6.2 complaints per 1,000 policies sold and third to Skipton Building Society with 5.9.
St. James's Place Wealth Management was fourth in the category having received 3.9 complaints per 1,000 pension and decumulation policies sold.
The latest pensions complaints table painted a similar picture to the second half of 2018 which also saw Coutts at the top of the chart.
Overall, the data showed an increase in total complaints from 3.91m in the second half of 2018 to 4.29m for the first half of 2019.
The FCA said the increase in complaints was mainly driven by a 34% jump in the volume of Payment Protection Insurance (PPI) complaints received, from 1.58m to 2.12m. PPI complaints made up 49% of all complaints received during this period, continuing to be the most complained about product, it added.
However, while PPI complaints increased in the first half of 2019, there was a 6% drop in the number of non-PPI complaints, from 2.32m in 2018 H2 to 2.18m in 2019 H1.
The FCA said: "When PPI is taken out, the figures today are the lowest volume of complaints firms have received since new reporting rules came into effect in 2016."
Excluding PPI complaints, the most complained about products remained current accounts (14% of reported complaints), credit cards (8%) and motor and transport insurance (6%).
Overall, excluding PPI, the average redress per complaint upheld increased from £175 to £200 between 2018 H2 and 2019 H1.
Staff are your responsibility
More than 4,500 retail investors affected
Failure to engage
Paid out £54m in related compensation