Ticket sales for the ongoing Expo 2010 Shanghai have been "satisfactory", organizers said on Friday, adding that public interest was escalating.

As of May 26, a total of 37.7 million tickets had been sold since sales began last March. About 4.9 million tickets were sold after the extravagant six-month fair officially opened on May 1.

About 70 percent of tickets that were sold before the Expo opened were purchased by bulk buyers, like companies, organizers said.

However, since the fair opened, bulk purchases have dropped dramatically to around 6.6 percent, they added.

Of the total ticket sales, individual tickets took up the lion's share, with 27.76 million sold, while group tickets issued by tourism agencies stood at 9.9 million.

The sale of night tickets, which allow visitors to enter the Expo Garden after 5 pm, has been "satisfying" at about 300,700.

Organizers are expecting sales to escalate as summer descends.

"The public's interest in the Expo has been rising by the day, with an increasing number of people entering the Expo Garden in the past several days," Chen Zhuofu, director of the ticketing center of the Bureau of Shanghai World Expo Coordination, said at a press conference on Friday.

The number of visitors organized by tourism agencies will hit 180,000 on May 29, Chen said, adding that "multiple conveniences are offered to group visitors, such as special entrances, reserved parking lots and reserved vouchers for popular pavilions".

Xu Wei, the Expo spokesperson, said bringing more visitors to the Expo is just one goal, while the other is to ensure every visitor has a pleasant experience.

Early estimates had put the number of visitors to the six-month Expo at 70 million, with a vast majority from China.

To achieve the target, the fair needs to attract 380,000 visitors a day.

"We expect more visitors but we are also concerned if the queues at some pavilions get too long," he said.

On Wednesday, staff at the Saudi Pavilion warned visitors they might have to wait in line for up to eight hours to get a glimpse of the structure, shaped like a moon boat.

The waiting area in front of the pavilion, which can accommodate around 10,000 adults, was fully packed half an hour after the Expo gates opened, a pavilion official said.