The new offer still included a once-off payment of R4 500, spokesperson Mpumi Sithole said on Wednesday.
In addition, workers had also been given two more options to choose from.
"[They are] a pre-tax stand-alone allowance of R600 [per month] or a salary increase of R400 per month," she said.
The options would be effective as soon as they returned to work.
The National Union of Mineworkers (NUM) regional co-ordinator for Rustenburg, Mxhasi Sithethi, said the strike committee would now go to the striking workers and tell them about the latest offer.
Negotiators would then return to the company on Thursday with the workers' response.
The company has been offering workers deadline-driven incentives to return to work at its Rustenburg, Amandelbult and Union mines, where operations have been at a standstill for eight weeks over a pay increase demand.
Extended deadlines ignored
Workers have not accepted previous offers.
The R4 500 allowance as already offered includes a loyalty or hardship allowance and a safe start-up allowance.
The company also said it would open next year's salary negotiations early, but any agreement would only apply from July.
It has already fired 12 000 striking workers from its Rustenburg operations, but has tried to take them back on condition they arrived for work by certain dates, which has not happened.
The company had given workers until Monday to accept the R4 500 offer, then extended it to Wednesday.
Asked whether the deadline was extended again, Sithethi said: "We have engaged with management. There is no deadline anymore."
He said deadlines hinged on dismissals, but now time would be spent on discussing and reviewing the offer made.
However, people were still not back at work, he said.
Discontent with NUM representation
Mametlwe Sebei, a member of the miners' national strike committee – a grouping formed as workers expressed discontent over how NUM was representing them during salary negotiations – said the company's increase offer was "a very important step forward".
"This is an actual increase, this is not just a go-back-to-work offer. It is constructive."
Workers at the start of their strike said they wanted a salary of R12 500.
He said he had never seen such unanimity among striking workers pressing for better pay.
"Usually by this time there is a far bigger layer of workers that want to go back. Even I was surprised by how resolute the workers are," Sebei said.
Meanwhile, Limpopo police spokesperson Lieutenant Colonel Ronel Otto said 56 people were arrested on Tuesday after stones were thrown at vehicles passing the Bukoni mine in Limpopo, near Apel, which is 49% owned by Amplats.
She said people allegedly set a tuckshop on the mine's property alight and threw stones at buses bringing people to work at the mine.
Three policemen were injured by stones.
"They threatened to burn property inside the mine and also some people working in the shafts were prevented from [coming and going]."
Police took action, using rubber bullets and tear gas, and over the course of the day and night arrested the large group.
The 56 arrested people would appear in Sekhukhune Magistrate's Court at a time still to be set.
'Random and arbitrary' arrests
The National Strike Committee complained that these were "random and arbitrary" arrests which included their chairman Elias Juba, and involved the use of police helicopters.
Sebei said he believed this was a "calculated strategy to demoralise striking miners".
In reply Otto said: "Police have a mandate to stop violence and protect property and lives of innocent people."
"In the process we identified people taking part in these events and if we can't arrest them on the spot, we will arrest them later," she said.
Those arrested would be charged with public violence and damage to property.
On Monday, police found the body of a Mozambican miner near a hostel at the company's Thembelani operations, also in Limpopo.
They also arrested 22 people on Monday in a protest at that mine.