About 75 percent of the scheduled flights in Europe on Wednesday were expected to take off, Eurocontrol said.

An airplane of British Airways is about to land at the Heathrow Airport in London, capital of Britain, April 21, 2010. The British authority reopened its airspace from 10:00 p.m. on Tuesday, which had been shut down since April 15 owing to the influence of volcanic ash from Iceland. [Zeng Yi/Xinhua]

The European Organization for the Safety of Air Navigation said in a statement that it "expects approximately 21,000 flights to take place today in European airspace. On a normal Wednesday, we would expect 28,000."

The agency said that almost all European airspace below 6,096 meters was available and air traffic services are being provided. Some restrictions are still in force in some areas, the agency said.

The Icelandic government said Wednesday that there are no signs of decreasing seismic activity under the Eyjafjallajokull glacier in southern Iceland but ash emissions have been considerably reduced.

Icelandair on Wednesday resumed most flights to the rest of Europe after a seven-day ban triggered by the ash clouds that spewed from the Icelandic volcano.

Reports from Iceland said Icelandair was to fly to London's Heathrow airport Wednesday afternoon from the Keflavik airport near Reykjavik.

The Paris airports - Roissy Airport and Orly Airport - were expected to restore 100 percent of their long-haul air traffic and 75 percent of their short and medium flights Wednesday, an airport spokesman told Xinhua.

Until 11:00 Paris time (0900 GMT), there had been 250 flights landing in and taking off from Roissy-Charles de Gaulles while there were 115 flights at the Orly airport, Jerome Landras, the Paris Airports Group spokesman, told Xinhua.

The DFS, Germany's air safety authority, said that German airspace has been opened to all flights and 16 international airports in the country have resumed normal flight schedules.

Meanwhile, Denmark extended the opening of its airspace to 8 a.m. Thursday, Danish air controller Naviair said.

The flight ban was lifted Wednesday night.

The Danish airspace was closed at 6 p.m. last Thursday due to a large volcanic ash cloud that drifted over much of Europe from Iceland and forced the cancellation of hundreds of flights and stranded thousands of travelers.

Scandinavian airline SAS said it expected to resume its full schedule of flights Thursday.

Poland's air space remained closed until further notice, Polish Air Navigation Services Agency (PAZP) said Tuesday. Poland's national carrier LOT said all of its flights have been canceled and it would take two to three days to resume operations.

The Icelandic volcano belched out a huge ash cloud on April 14, causing air travel chaos across Europe. Airlines in many European countries canceled about 100,000 flights from April 15-21, Eurocontrol said.