More than 2,000 AMP drivers are eligible across the UK for the scheme and more than 300 have already ordered cars through the scheme since it was set up earlier this year.
AMP chose to go down the ECOS route in 2000 and spent more than a year investigating possibilities before settling on a provider to work with.
David Matthewson, group transport manager of AMP, said: 'With such a tight deadline it was essential that everyone focused on the live date and the LeasePlan team worked with us every step of the way to make our scheme happen on time.
'The initial sales team stayed in place until after the launch, ensuring they knew the scheme as well as we did and did everything possible to speed us through the process with as little trouble as possible.
'The fact that the same people didn't just sell us the scheme, but also implemented it was critical to the success of the project.'
From its launch AMP was faced with the challenge of communicating the benefits of the scheme to the large staff base. Matthewson added: 'The company is experiencing great change and clearly communicating the alteration in the car policy was more important than ever.
'Many employees have had a company car since the 1970s or 1980s and have almost been unaware of the amount of tax they were paying for it.
'Communicating that this 'hidden' money could now be saved for them has been an uphill task coupled with the fact that each employee now has to work out what they want from their new car and how best to get this through the scheme.'
However, he said that with a clear communication strategy in place from the project team and LeasePlan the challenges would be overcome.
LeasePlan commercial director Kevin McNally said: 'In our experience working with many different organisations to provide ECOS, we have found that unless the whole organisation has accepted the idea it will not work to its best ability, regardless of the financial benefits.
'Rather than trying to enforce a scheme on to the company's employees, we work with a project team across all the relevant departments who ensure every person affected has all the information about the project they need, and feels comfortable with what they are being asked to undertake.'