Fractional aircraft share sales strengthened in 2013 for NetJets, leading the fractional ownership provider to a 7.5% increase in revenues and a 7% improvement in earnings, NetJets parent Berkshire Hathaway reports.

NetJets’ increase in revenues was slightly behind other businesses in Berkshire Hathaway’s “other service” group, which also includes FlightSafety International, TTI, Business Wire and Dairy Queen, among others. The businesses reported in that group collective contributed to a 10% increase in revenues to $9 billion in 2013.

NetJets’ revenues increased $288 million – which, according to the reported increase, would put its revenues on the year at about $4.128 billion (Berkshire Hathaway does not typically break out revenues for either NetJets or FlightSafety). Berkshire attributed the increase to higher fractional sales.

Along with the increase in revenues, Berkshire Hathaway credited both NetJets and FlightSafety for helping lead the other services businesses to a $130 million increase in pre-tax earnings to $1.1 billion.

The 7% improvement in NetJets earnings not only came on increased fractional sales, but improved margins in those sales along with improved flight operation margins, Berkshire Hathaway reports. The operator also had reduced net financing costs. These improvements “more than offset the increase in comparative aircraft value impairment charges,” Berkshire Hathaway reports.

FlightSafety’s earnings, meanwhile, improved 11% in 2013 as its training revenues increased, but operating expenses remained relatively unchanged, Berskshire reports.

The improvement in earnings is welcome since Berkshire Hathaway notes “the improvement in earnings of NetJets and FlightSafety in 2012 were relatively unchanged from 2011.” It also continued the slow but steady turnaround for NetJets since 2009, when it lost more than $700 million, laid off hundreds of workers and began downsizing its fleet.

NetJets now claims a fleet of more than 700 aircraft – but that includes the Executive Jet Management fleet of managed aircraft – and employs more than 6,000 workers.