There is a new effort to reopen a number of rail lines in south-western New South Wales.

The Cootamundra to Tumut branch line is 104 kilometres long and includes a Murrumbidgee River floodplain crossing in Gundagai.

The line closed in 1984 when sections near Cootamundra were damaged by floods.

A Request for Tender (RFT) from Transport for NSW is now out to restore, operate and maintain the line on a commercially sustainable basis without state government funding.

Transport for NSW said the tender was an example of the government working with industry and using a commercial approach to develop a strong freight transport network in the state.

Visy Industries founder, Dick Pratt, wanted rail instead of using roads when he built his first pulp and paper mill at Tumut, but it never eventuated, with freight still leaving the mill by truck.

In 2005, Visy said it supported reopening the Tumut to Cootamundra line and was prepared to invest in the rolling stock.

Since then, output from the mill has doubled to 700,000 tonnes of paper per annum.

Last year, the state government announced $70m over five years to upgrade the Gocup Road, partly to help service the Tumut mill and allow trucks to take bigger loads and reduce the number of truck movements on local roads.

The Request for Tender also covers the 22 kilometre Yanco to Whitton section of the Hay branch line, and land in the rail corridor at Yenda, Leeton, Binya and Coolamon.

The RFT opened in November and was to close last week, but has been extended to May 25.