"We have eliminated the 256Kbps speed and Optus DSL broadband customers will now receive at least 512Kbps downstream speed," said Optus' consumer group marketing director Michael Smith in a statement.
Optus has also overhauled its pricing structure for ADSL services, in the process allocating larger download limits.
"Extensive research by Optus showed customers wanted plans that are easy to understand and improved broadband services," said Smith.
"With the increased use of broadband for music, education and entertainment, speed and download limits are more important to customers."
Optus has also extended its off-peak time zone -- which comes with separate and higher download limits than its on-peak times -- so that it lasts from midnight to midday each day.
Optus' new plans offer customers a range of download limits at two speeds (512Kbps and 1.5Mbps), with prices ranging from $39.95 per month to $79.95 per month. Customers who bundle their broadband plans with either an Optus fixed or mobile phone line receive $10 off their broadband plan monthly charge.
Customers who exceed their download limits will have their connection cut down to dialup speeds.
The new plans come as Optus has recently quietly retreated on its stated plans to offer customers migrating to its new ADSL infrastructure speeds up to 20Mbps. However ZDNet Australia understands the speeds have not yet been finalised and may change before the company formally launches its new, high-speed ADSL hardware to the market.