NEW YORK — Sales of store brand merchandise in the mass channel (mass merchants, club stores and dollar stores) increased last year on a dollar basis and a unit basis, the Private Label Manufacturers Associated (PLMA) said on Wednesday, citing sales data from Nielsen.

Dollar sales rose 9.3% in 2017 and unit sales increased 9.1%, PLMA said. In contrast, sales of national brands declined 0.3% in dollar terms and fell back 1% in unit volume.

“The mass channel is an ongoing store brands success story,” PLMA said in a statement. “Since 2015 alone, annual store brand dollar sales in the sector have increased by $7.5 billion, a gain of 15.8%.”

Thanks entirely to store brands, overall sales in the mass channel during 2017 grew by 1.3% in dollar terms and 1% on a unit basis, PLMA said. Total store brand dollar sales were $54.9 billion, up from $50.2 billion in 2016. In terms of unit volume, store brands rose to 17.9 billion in 2017 from 16.4 billion a year earlier.

Store brands in 2017 grabbed another 1.3% of the market in the mass channel, ending the year with a record high 18% share, in dollar terms, PLMA said. On a unit basis, store brands increased their market share by 1.6 percentage points to 21.4%, also an all-time high for the mass channel.

“The results in the mass channel for 2017 pushed Nielsen’s store brands figures to positive territory across all outlets combined, despite weak performances for private label in supermarkets and drug stores,” PLMA said. “For total outlets, dollar sales for store brands were up 2.7% and unit volume rose 1.4%.”