LONDON (The Deal) -- European markets drifted upward on Friday, as traders bet on renewed economic stimulus from the European Central Bank in the coming weeks following weaker eurozone data.

Watch the video below for a look at how European markets are doing in midday trading Friday:

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A month-on-month fall of 1.4% in German retail sales in July and continuing falls in Spain, coupled with wholesale price declines in France for industrial and food products, all point to a further decline in inflation. The flash reading of 0.3% for the eurozone consumer price index from Eurostat seemed to confirm that trend. A spate of poor economic figures from Japan, which is still trying to pull itself out of its decade-long deflationary slump, added to the pressure for the eurozone bank to act before Europe enters a similar swoon.

By mid-morning, London's FTSE 100 was up 0.10% at 6,813, while in Paris the CAC 40 was also up 0.10% at 4,370. In Frankfurt, the DAX was up 0.12% at 9,474. Nevertheless, the markets continue to keep a wary eye on developments in Ukraine, and the German market in particular has seen some volatility over the past few days as events there unfold. Moscow's MICEX Composite was down 0.53% at 1,416.

But it wasn't geopolitics as much as geology and industrial relations that left German airline Deutsche Lufthansa  (DLAKY) as the weakest performer in the German blue-chip index. Lufthansa's share slid 1.95% to 13.10 euros in part because of a pilot's strike at its budget subsidiary German Wings, and partly on fears a volcanic eruption in Iceland could disrupt European and transatlantic travel in weeks to come.

In London, the supermarkets were the biggest fallers, after Britain's largest, Tesco (TSCDY) , issued a profit warning, slashed its dividend and brought forward the starting date for its new CEO Dave Lewis. Lewis seems to be following a move set a decade ago by Justin King when he started the role at Tesco rival J. Sainsbury. King also slashed the dividend and announced a big loss to start his planned turnaround with a clean slate. But with consumers rapidly switching from mainstream grocers to discounters, Tesco's recovery may be harder to achieve.

Tesco was down 6.09% at 231.3 pence, Sainsbury's was down 4.48% at 289.90 pence and the already struggling Wm. Morrison was down 4.28% at 178.90.

In Tokyo, the Nikkei 225 closed down 0.23% at 15,424.59, while in Hong Kong, the Hang Seng closed virtually unchanged at 24,742.06. The Shanghai Composite ended the day up 0.97% at 2,217.20.