The Scottish Government has awarded over £9.75m to 19 bus and coach operators to retrofit 594 vehicle exhausts over the next financial year.
The funding comes under the third phase of the Bus Emissions Abatement Retrofit (BEAR) scheme.
Click here for full details of the funding allocations, including £3m for First Glasgow to upgrade 165 buses or coaches and £2.2m for Lothian Buses to upgrade 188.
The technology will reduce nitrogen dioxide and particulate emissions from older buses and coaches through the installation of specialist exhaust technology by accredited providers.
These retrofits will achieve the latest Euro VI standard, which is the equivalent to emissions from a modern diesel bus, ministers said.
Transport Scotland and Energy Saving Trust will also be monitoring emissions performance from the retrofitted vehicles to ensure they perform effectively over time.
Cabinet secretary for transport, infrastructure and connectivity, Michael Matheson, said: 'The Bus Emission Abatement Retrofit Fund benefits Scottish retrofit businesses, our wider bus sector and helps protect public health.
'It’s a high-impact fund, which provides a powerful combination of immediate economic stimulus to our valued bus and coach sector and supply chain, whilst supporting our strategic air quality objectives by helping operators to comply with forthcoming Low Emission Zones.
Stewart McLean, managing director of Driveline – a business based in Grangemouth and a supplier of the accredited exhaust retrofit technology said: 'This is a great opportunity for Driveline to help Scottish operators improve their emissions and demonstrate the successful Euro VI product lines that Driveline now offers to the world.'
Claire McVicar, Environmental Officer at Lothian Buses said: 'We are fully committed to improving air quality across all our operations in Edinburgh and The Lothians through our ambitious Bus2020 strategy, in line with the Scottish Government’s Climate Change Targets. We are therefore delighted to receive this substantial funding contribution from the Scottish Government to assist us in achieving our environmental goals.'