Market researcher Kantar Worldpanel said Aldi scored another all-time record share of 3.6 percent in the 12 weeks to June 9, while Lidl and Waitrose both held on to record shares from May of 3.0 percent and 4.9 percent respectively.
Market leader Tesco, No. 2 player Asda and No. 4 Wm Morrison all saw their share dip.
Only No. 3 J Sainsbury bucked the trend, raising its share to 16.7 percent with sales growth of 3.5 percent, ahead of overall market growth of 3.0 percent.
"The continuing polarisation of the grocery market poses a difficult question for the big four retailers - how to make their offer appealing in an increasingly squeezed market," said Kantar analyst Fraser McKevitt.
"Asda recently announced it is going toe-to-toe with Aldi on the price of fresh food and produce, demonstrating its growing concern with the threat from the discounter."
Earlier this month Tesco reported a first-quarter like-for-like sales fall of 1 percent, while Sainsbury posted a 0.8 percent rise.
Last month Morrisons reported a first quarter decline of 1.8 percent, while Asda posted a 1.3 percent rise.
All four updates were, however, for slightly different time periods.
Kantar said grocery inflation for the 12 week period was 3.9 percent.
Following is a summary of market share and sales.
Market share (percent)
| 12 wks to | 12 wks to | pct change | |
| June 9 2013 | June 10 2012 | in sales | |
| Tesco | 30.5 | 31 | 1.3 |
| Asda | 16.9 | 17.2 | 1.1 |
| Sainsbury | 16.7 | 16.6 | 3.5 |
| Morrison | 11.6 | 11.8 | 1.2 |
| Co-operative | 6.3 | 6.5 | -1.3 |
| Waitrose | 4.9 | 4.6 | 10.4 |
| Aldi | 3.6 | 2.8 | 29.9 |
| Lidl | 3 | 2.8 | 8.5 |
| Iceland | 2 | 2 | 5.2 |
