Shares in Europe's biggest supermarket operator Carrefour (CRRFY) fell 2.6% Friday to €21.07 ($22.40) after UBS and Goldman Sachs published negative notes ahead of the group's first quarter sales report next week.

UBS cut Carrefour to "neutral" from "buy" on concerns about the group's margins in its home market of France, where it saw signs of renewed erosion due to an escalating price war with rivals such as Casino (CGUSY) and co-operative E.Leclerc. UBS cut its stock rating despite increasing its price target to €24.50, up from €19.50.

Goldman maintained its neutral rating on the stock but lopped about 2% of its earnings per share estimates for the period from 2017 to 2019 and cut its 12-month price target by €0.40 to €21.60 to reflect "recent trading and FX" movements.      

Carrefour, sometimes referred to as Europe's Walmart(WMT) - Get Report , is due to release its first quarter sales figures on April 13. Investors will be hoping for signs that the company has managed to stem declining profits in its home market and that the company's forecast rebound in Asian sales is underway. Carrefour's French margins slid 80 basis points over the second half of 2016, their biggest half year decline since the start of 2011, due to pressure from rivals and despite a massive overhaul of the group's biggest supermarket outlets and a shift toward higher-margin convenience formats.  

Carrefour CFO Pierre-Jean Sivignon has promised improvements in 2017, claiming that the 2016 results were hurt by the cost of transforming the recently acquired, and loss making, network of 400 Dia supermarkets. CEO Georges Plassat, meanwhile, promised that a decline in Asian sales would begin to rebound as "China is now bouncing back."

Sales in Brazil will also come under the spotlight. The Brazilian real has strengthened against the euro this year, and should provide a boost to earnings so long as Carrefour has maintained sales growth that topped 16% over 2016. The Brazilian real has traded at nearly €0.3 of a euro for most of this year, up from lows of €0.23 in early 2016.

Carrefour should post total revenue for 2017 of about €83.6 billion, up 6% year on year, and a EBITDA of €4 billion, up 5.9%, according to Goldman Sachs. 

Carrefour shares are down 8% year to date, compared to a 10% gain in France's CAC 40 index.