(Reuters) - Boeing Co BA.N delivered 61 of its best-selling 737 single-aisle aircraft in September, unexpectedly surging past numbers for August and suggesting manufacturing problems at suppliers may be easing.

Signage for Boeing is seen on a trade pavilion at Farnborough International Airshow in Farnborough, Britain, July 17, 2018. REUTERS/Toby Melville

The news briefly pulled Boeing shares back into positive territory in afternoon trading, on a day when industrial stocks were being weighed down by concerns over trade and China’s growth.

Boeing's production has been hit by delays at suppliers such as fuselage maker Spirit AeroSystems Inc SPR.N and GE joint venture CFM International, which makes engines for the 737s, resulting in deliveries of just 29 planes in July.

The bounce to 48 planes in August offered hope that the company could still make good on its target to deliver 50 more airplanes overall in 2018 than last year’s record 763.

Chief Executive Officer Dennis Muilenburg said last month only that September deliveries of the 737 narrowbody jetliners would be as good as August.

Boeing’s quarterly numbers indicate ongoing progress with suppliers and set the world’s biggest aircraft producer up for a strong finish to the year, said Jefferies analyst Sheila Kahyaoglu.

“We expect a full recovery in the fourth quarter,” Kahyaoglu said.

The numbers brought overall aircraft deliveries for the first nine months of 2018 to 568, up from 554 at the end of September a year ago.

Boeing, which aims to deliver between 810-815 planes in 2018, is in front of its main rival Airbus SE AIR.PA, which delivered 503 aircraft through September this year, up from 454 aircraft deliveries in the same period last year.

Boeing delivered 57 planes in September last year.

Europe's Airbus SE AIR.PA has been grappling with delays to deliveries and quality problems, leaving it a steep trajectory in deliveries for the fourth quarter in order to meet end-year targets.

Deliveries so far this year included eight of the recently acquired Bombardier CSeries, now known as the A220. The Toulouse, France-based company expects to deliver about 800 planes in 2018, excluding the Canadian-designed A220.

Boeing is also ahead in the order race with Airbus, booking 631 net aircraft orders after cancellations in the first nine months of the year, well ahead of the 256 orders recorded by Airbus.