Two new teams will be welcomed into the Southern Electric Premier League (SEPL) in 2013.
And the competition will switch to a four-division structure, with 10 sides fighting for honours in each one as they play against their rivals both home and away.
The change will not affect the existing division one and division two, where Hambledon will ply their trade next summer.
However, at the end of the 2012 season the third division - which currently contains 18 teams - will be split.
The top 10 sides will make up the new division three, while two new clubs from the Hampshire League will join up with the bottom eight to form division four.
'It will introduce much more competition into division three - something that has been lacking in the past,' said SEPL chairman Paul Thompson.
'Many sides reach mid-season without anything to play for.
'But this means there will be plenty for the existing division three clubs to play for next summer, with the highest placed sides forming the new division.
'Division two was hugely competitive this season.
'Ventnor won it with some ease but at the other end of the scale, as many as six clubs were in the relegation mix until the last few weeks of the season.
'The final demotion place was undecided until the very last day of the season.'
The SEPL's plans to increase its playing numbers by two from 38 to 40 in 2013 has already prompted Dorset League champions Poole Town to make enquiries about joining.
Near neighbours Parley, who play their home matches at Dean Park, are also expected to beef up the interest they have shown previously.
Meanwhile, any existing Hampshire League club wanting to join would need to have their ground and junior set up accredited by the Hampshire Cricket Board.
Hampshire League division one runners-up Locks Heath and Waterlooville will be among the interested parties but both clubs have ground accreditation problems to overcome.
Next season's summer programmes will begin on May 5, with Dan Hewitt's Hambledon hosting Andover in SEPL division two on day one.