AIM-listed Clean Air Power has signed a letter of intent to begin the first phase of a production development programme for a MicroPilot diesel-natural gas engine for the South East Asian and other markets.Clean Air, which develops compression-ignited natural gas systems and software for heavy duty vehicles, expects to begin the programme will take around six months to complete and will result in revenues of more than $3m.If successful, the programme will then enter a second phase that would focus on bringing a MicroPilot diesel-natural gas engine for the South East Asian and other markets to the start of production in 2017.Chief executive officer John Pettitt said: "We are delighted to be moving from the concept phase to the first phase of production development on a MicroPilot diesel-natural gas engine with the potential to deliver a significant improvement in performance and efficiency."Our client is a progressive, global truck manufacturer with a bold ambition for the future application of compression-ignited natural gas engines. Its commitment to move ahead with this next phase demonstrates the quality of our technology and the value that our relationship with Ricardo can bring to original equipment manufacturer (OEM) partners."Our ambition is to become a global design, development and delivery partner of compression-ignited natural gas engines and we are excited about the potential of this latest success to open the door to other OEMs partnerships."