Gearbox designer Torotrak posted an operating loss for the six months to end of September after it received fewer licensing revenues.
The Lancashire-based group, which develops fuel-efficient gearboxes, reported revenue of £1.7m for the half-year to end-September compared to £4.7m the same time a year earlier. It reported an operating loss of £1.5m during the half-year period from a profit of £1.4m before.
"As in previous years, the group's revenue continues to be dominated by the timing and quantum of up-front licence payments from major customers," it said.
As well as lower licensing revenues, Torotrak booked a £0.4m increase in development expenses, which was partly offset by a £0.3m drop in administrative expenses.
During the period, the group received court approval to cancel £53.7m being held in the share premium account.
Looking ahead the group said: "It is well positioned to take advantage of the opportunity to offer Tier 1s and/or OEMs efficient, cost-effective hybrid products to meet their emissions reductions targets whilst maintaining performance and driveability."
Dual-fuel engine management system developer Clean Air Power said annual losses were likely to be better than expected despite sales running slightly behind market hopes.
Clean Air Power, which develops technology for heavy duty vehicles, said losses in the period to December 31st this year were likely to be marginally smaller than market forecasts as a result of a different sales mix.
Clean Air Power said it had sales and forward orders to date in 2013 of more than 400 units, compared to 300 in the whole of last year.
It had achieved that despite constraints on expected production levels of methane-diesel vehicles by its European manufacturing partner ahead of the launch of Euro
6 emissions standards in Europe in 2014.
"Demand for our products is expected to continue to increase in 2014 due to interest from several large UK fleet operators and the opening of a number of new natural gas refueling stations," the group said in a trading update.
"In addition, there will be an increased supply of vehicles available to retrofit as a result of the high level of late Euro 5 vehicle purchases made by operators ahead of the imminent change to Euro 6."
But Clean Air Power revealed that although high activity on a US project had generated a slight increase in the level of grant revenue now expected in 2013 from the Californian Energy Commission, there were issues that meant it now expected to launch its US product in the second quarter of 2014.
Chief Executive John Pettitt commented: "Growing demand for our Dual-Fuel products in Europe has seen orders in 2013 significantly exceed those in the full year 2012 and I am hopeful orders will continue to rise."