Sportsmatch has appointed GEM Group to 'open additional channels in parliament and among civil servants', said Reynolds.
The body matches about £3m a year in funding from the Government with private businesses contributions, said Sportsmatch director Mike Reynolds.
He predicted that private sector contributions could treble within two to three years, necessitating a rise in government funding to match it.
'The Government has many calls on funding, but one of our jobs is to show how effective we are at utilising it and persuade it that (grassroots sport) is worth more funding.'
'GEM's knowledge and contacts in Whitehall and Westminster will be useful,' he added.
Reynolds said the lobbying effort would focus on promoting Sportsmatch as value for money, and emphasising the importance of the private sector in funding sport.
GEM account director Dan Parr leads the account, reporting to Reynolds.
The agency, which began work on the brief today (1 April), will also develop a national media relations campaign targeting print and broadcast outlets.