The expansion of one of Victoria's largest abattoirs can go ahead, creating about 800 jobs on Melbourne's fringe, the state government says.

O'Connors is planning a $315-million redevelopment at its Pakenham facility southeast of Melbourne.

Planning Minister Matthew Guy says the state government has amended the local planning scheme to allow the expansion to occur.

He said the development would create about 800 jobs and benefit the entire region.

"This investment will be a great shot in the arm to the economy of the southeast," Mr Guy said in a statement.