The Cabinet Office will provide £496,808 to fund the website, which helps charities, voluntary groups and social enterprises find funding and finance opportunities in England.
The funding will be split roughly in half between the NCVO and its partner, the software developer Idox Information Solutions.
According to figures from the NCVO, about £100m was secured by charities through the free service last year. The site has more than 50,000 registered users.
Sir Stuart Etherington, chief executive of the NCVO, said: "Funding Central is a shining example of a successful partnership between the public, private and voluntary sectors.
"In its lifespan the service has added real value and connected a diverse range of organisations with opportunities to grow and diversify their income."
Last year, users who successfully bid for funding secured an average of £35,068 per organisation, NCVO figures show.
The Cabinet Office said the decision to extend the service for a further 18 months was made in the light of information that it was the most commonly used web resource for organisations that wanted information on funding.
Nick Hurd, the Minister for Civil Society, said: "Last week I published a progress update outlining how the government intends to work with civil society to deliver better regulation, better support and better skills.
"Our agreement with the NCVO to extend Funding Central until March 2014 is a practical and meaningful demonstration of our commitment to the sector and a vote of confidence in a proven and valuable resource."