The strength of the high-end-large business jet segment and a surge in twin turboprop deliveries helped increase industry billings by nearly one-third in the first quarter, even as the light jet market continues to stumble, according to the General Aviation Manufacturers Association (GAMA).

General and business aviation manufacturers shipped 458 aircraft in the first quarter, a nearly 10% gain over the 418 shipped in 2012, GAMA says in its first-quarter 2013 shipment and billings report released May 9. Billings, meanwhile, jumped 31.7%, from $3.5 billion in the first quarter of 2012 to $4.6 billion in the most recent quarter.

Bombardier was the driving factor behind the improved returns, shipping 10 more business jets in the first quarter than it did a year earlier. Its mix of shipments also tilted toward much higher billings, with 17 of its high-end Globals handed over to customers compared to just four a year earlier. Bombardier had slowed Global deliveries early last year while it switched flight decks on the aircraft.

Embraer also helped the improved industry performance with four Legacy 650 deliveries, compared with just a single Legacy 600 a year earlier.

These offset a slower quarter at Dassault, which saw deliveries decline from 15 to eight aircraft in the first quarter. And despite the increases at Bombardier and a slight uptick at Embraer, business jet shipments were up just 4% overall, from 124 deliveries in first quarter 2012 to 129 in the most recent quarter.

Light jets continued to struggle in the first quarter, with Cessna business jet deliveries down five and company executives announcing plans to slow production further. Bombardier’s Learjet deliveries, meanwhile, remained at a trickle with three aircraft, as the company prepares to transfer lines from the 40XR/45XR to the 70/75. Embraer’s light jet deliveries were flat in the quarter.

A notable increase in the quarter comes in the twin-turboprop category, which was up nearly 80%, from 19 aircraft in the first quarter of 2012 to 34 this year. Beechcraft, which finished out the first quarter as a new company emerged from bankruptcy, delivered almost twice as many of its King Airs.

Strong agriculture sales are helping prop up the turboprop category overall as single turboprops increased 14.6%, from 89 in first-quarter 2012 to 102 in the most recent quarter, according to GAMA.

Even the piston segment fared better in the first quarter, inching up 3.8%, from 186 in first-quarter 2012 to 193 in the first three months of this year.

GAMA notes the positive returns throughout the major segments, but that performance was mixed within the segments. GAMA President and CEO Pete Bunce says the mixed results “demonstrate the need for the industry’s continued engagement with elected officials and regulators throughout the world as we seek to strengthen the GA sector.”