* Workers reject 9.5 percent pay rise offer
* Five-week long strike to continue
* Northam says open to further talks
(Adds Northam comments)
By Olivia Kumwenda
JOHANNESBURG, Oct 6 (Reuters) - Northam Platinum, one of South Africa's smaller platinum producers, said on Wednesday a strike at its South African mine had cost about 250 million rand ($36 million) so far in lost revenue.
Workers rejected Northam's latest pay offer of a 9.5 percent rise and a housing allowance of 1,750 rand a month, South Africa's National Union of Mineworkers (NUM) said.
Northam said in a statement it remained committed to further talks to end the five-week long strike after the workers rejected its revised offer.
"Employees in the affected categories have lost approximately 60 million rand in wages and benefits," it added.
The NUM is demanding a 15 percent increase and a housing allowance of 3,500 rand.
"The offer was rejected and the strike continues," said Zwelitsha Tantsi, NUM's chief negotiator at Northam.
South Africa, the continent's biggest economy, has been hit by a wave of strikes and strike threats, which have led to pay settlements well above the inflation rate and have raised fears that the cost of living will rise.
A smaller union, Solidarity, last week signed a wage deal with Northam, while NUM had rejected the offer.
Northan said in early September the strike at the Zondereinde mine would cost 1,000 ounces per day in lost production of platinum group metals (PGMs).
South Africa's inflation rate was 3.5 percent in August.
($1=6.891 Rand) (Editing by Jon Herskovitz and Jane Baird)