The Independent's poor results come during the same week that Denis O'Brien, the Irish telecoms and media tycoon, spent around £21m increasing his share in Independent News & Media to 8%.
The daily market was split down the middle with five titles -- The Guardian, The Times, the Daily Mirror, the Daily Star and the Daily Express -- reporting minor increases in monthly circulation and five papers -- The Sun, The Daily Mail, The Daily Telegraph, the Financial Times and The Independent -- all suffering a small decrease in sales.
The daily newspaper market consisted of 11,572,499 copies in May, up 0.26% from the month of April, but its six-month average is still down 3.56% to 11,630,701 copies.
The Independent continued its decline during May, with circulation dropping 1.63% to 245,466 copies. Its six-month average is also down 1.83% to 251,977 copies.
The Daily Telegraph also suffered a slight decrease in sales, down 0.51% from April to 894,258 copies. Its six-month average is down 0.38% to 898,938.
The Financial Times reported only a minor slump, down 0.04% to 452,767 copies for May, but its six-month average is up 0.47% to 448,970, which is the only national daily to report a rise in year-on-year figures this month.
The Guardian continued increasing its sales during May, reporting a 1.42% increase in monthly circulation to 371,754. Its six-month average is down 3.34% to 369,143 copies.
The Times improved on its poor performance in April, selling 636,777 copies, which is up 1.21% month-on-month although it is down 3.84% year-on-year to 641,428 copies.
In the mid-market sector, the Daily Express further capitalised on a good performance in April, reporting a 0.77% rise in circulation figures in May to 765,967 copies. However, its six-month average is down considerably to 764,898 copies, which is a 7.87% decrease year-on-year.
The Daily Mail suffered a slight drop in circulation, down 0.24% in May to 2,294,929 copies and its six-month average is down 2.48% to 2,324,032.
In the red-top sector, The Sun was the only paper to suffer a fall in sales, although only slight, down 0.14% to 3,043,351. Its six-month average is down 2.91% to 3,067,057.
The Daily Mirror experienced a rise in circulation in May to 1,554,610, up 1.14% month-on-month. Its six-month average is down 6.26% year-on-year to 1,557,382 copies.
The Daily Star reported positive circulation results, up 1.03% to 778,249 copies in May. Its six-month average is down 2.14% year-on-year to 770,478.
The Independent on Sunday dropped 14.46% on April to 209,418 copies, with its six-month average down 4.4% year-on-year to 226,546. The paper unveiled a radical redesign this month in which the separate sections were merged into the main paper.
The rest of the Sunday quality papers were also down, with The Sunday Times falling 0.78% on April to 1,221,590, with its six-month average down 7.48% year-on-year to 1,240,811.
The Sunday Telegraph is down 1.78% on April to 655,047 and its six-month average is down 3.14% year-on-year to 654,453.
The Observer is down 2.54% on April to 451,363 and its six-month average is down 7.09% to 449,182.
In the mid-market The Mail on Sunday fell 2.53% on April to 2,274,551. Its six-month average is down 1.82% to 2,276,590. In contrast, the Sunday Express climbed 0.76% on April to 744,902, although its six-month average is down 8.49% year-on-year to 773,124.
In the popular market the biggest monthly change was for the Sunday Mirror, down 1.58% to 1,377,534. Its six-month average is down 6.61% year-on-year to 1,382,643.
The News of the World dropped slightly by 0.35% to 3,270,753 and its six-month average is down 6.43% to 3,335,374.
The People climbed 1.12% from April to reach 729,715. However, its six-month average is down 14.19% to 741,484.
Finally, the Daily Star Sunday dropped 0.52% on April to 381,241 and its six-month average is down 4.65% to 375,281.