"We are meeting with unions. We hope an agreement will be reached," said spokesperson Sue Vey on Tuesday.
She said no formal demand had been presented to the company.
"We hear rumours … It is like a fight for control between unions."
Workers associated with the Association of Mineworkers and Construction Union (Amcu) went on strike on Tuesday, demanding that the National Union of Mineworkers' (NUM) offices at the mine be shut down with immediate effect.
Vey said on Wednesday the NUM had been given notice to vacate its office in July.
The workers, some wielding knobkerries, chanted as they marched to the stadium from the various shafts where they gathered on Wednesday morning.
Everything at a halt
On Tuesday, Amcu branch chairperson Mceli Balimani said Lonmin refused to close the NUM's offices, and said the NUM was given notice to vacate the offices by July 3.
Striking workers agreed at a meeting on Tuesday that they would report for duty on Wednesday, but would not go underground.
Vey said there were no operations at the mine on Wednesday, saying "everything has come to a halt".
"Everything has come to a halt. Management is meeting with unions as we speak."
Lonmin's platinum mine in Marikana was at the centre of a wildcat strike in the platinum belt last year, with 44 people killed – 34 of them at the hands of the police – in strike action.
Night shift
Vey said "the earliest shift to return would be the night shift" if workers and the company reached an agreement. The company employs 27 000 people and 10 000 contractors.
The latest disturbance at the mine near Rustenburg, 120km north-west of Johannesburg, comes after last week's murder of Mawethu Khululekile Stevens, a local organiser for the Association of Mineworkers and Construction Union. Four men entered a tavern and shot him as he watched television, the South African Press Association said, citing police.
Violence at the mine in August that erupted from a dispute over pay left at least 44 people dead, including about 34 who shot dead by police on a single day, 70 injured and led to about 250 arrests. A lengthy strike could threaten Lonmin's forecasts of increased output after saying this week that it plans to exceed production of 700 000 ounces of platinum metals in concentrate this year after the 2012 strikes cut volumes and raised costs.
Lonmin fell 6.4% to 37.70 rand in Johannesburg on Tuesday, the lowest since May 2. Anglo American Platinum, the biggest producer, declined 3.8% to R301, the worst level since September, 2005, while Impala Platinum Holdings dropped 5.1% to R98.89, its lowest since November, 2008.
The rand weakened less than 0.1% to R9.2407 per dollar by 8.15am in Johannesburg, its lowest level since April 2. – Sapa, Bloomberg