Anglo American Platinum Ltd., the world’s biggest producer of the metal, said 11 percent of its workers went on strike less than a week after a state-sponsored peace accord failed to win unanimous agreement from unions.

About 5,600 striking workers are demanding that suspended officials from the Association of Mineworkers and Construction Union are reinstated, the Johannesburg-based company known as Amplats said in a statement today. Aside from reversing the ban on the officials for joining a sit-in protest, the workers also want job cuts scrapped and a guarantee that a rival union be banished from Amplats mines.

The AMCU was the only labor union that last week refused to sign the agreement aimed at bringing stability to the South African mining industry as wage negotiations begin. Falling precious metal prices are constraining companies’ ability to meet union wage demands higher than a year ago, when strikes spilled over into violence that led to at least 44 deaths.

Workers at Amplats’s Thembelani and Khuseleka 1 mines have started an unauthorized strike, Amplats said in the statement. Production was disrupted at Thembelani last night and at both mines this morning, it said.

Jeff Mphahlele, general secretary for the AMCU, said some of the union’s members didn’t go to work at Thembelani, declining to give further details.

Today’s strike follows the suspension of AMCU officials by Amplats following alleged vandalism of offices belonging to the UASA union and a subsequent underground sit-in protest last month, said Franz Stehring, a UASA official.

Union Rivalry

Union rivalry between the National Union of Mineworkers and the AMCU, which has been winning employees from NUM, has escalated tensions at mines across the country. Last month miners at Thembelani, about 120 kilometers (75 miles) northwest of Johannesburg, temporarily trapped 2,400 of their colleagues underground as part of a union dispute.

The striking workers are demanding Amplats give a guarantee that NUM won’t be allowed to return to the company’s operations, Amplats said today.

The unions’ rivalry has led to three workers’ deaths since May in the Rustenburg area. Last year’s violence included the deaths of 34 protesters killed by police in a single day near Lonmin Plc’s Marikana platinum mine.

Amplats is planning to cut 6,000 jobs as part of an effort to return to profit by idling three shafts and reducing annual output by 350,000 ounces of metal. Talks with unions about the proposal are due to end on Aug. 10.

Court Action

Lonmin, the world’s third-largest platinum producer, said today that the NUM has brought a court application relating to its membership numbers and those of AMCU. The platinum producer said it couldn’t comment further before the hearing. NUM is disputing the authenticity of AMCU’s membership numbers, spokesman Lesiba Seshoka said last week.

“The company’s wider position remains that it wishes the issue of union status at its operations to be resolved peacefully, and as quickly as possible, for the benefit of all stakeholders,” Lonmin said in the statement.

Deputy President Kgalema Motlanthe was appointed by President Jacob Zuma to broker a solution to mine labor unrest, leading to last week’s peace accord. The agreement was signed by the Chamber of Mines, which represents producers, government departments and labor unions apart from the AMCU, which is led by former NUM official Joseph Mathunjwa.

Peace Appeal

“Anglo American Platinum would like to urge all employees and their union representatives to live by the spirit of the deputy president’s peace and stability framework and to promote the peaceful co-existence of all the recognized unions at our operations,” Amplats said in its statement.

While platinum has dropped 13 percent this year, gold is 27 percent lower. A weaker gold price is hampering the ability of producers of the metal to meet wage demands, according to the Chamber of Mines, which represents South African bullion miners.

The mines chamber today hosts a pre-wage negotiation meeting with unions aimed at winning agreement on how talks will be conducted.

Entry-level underground gold miners receive a minimum wage of 5,000 rand ($487) a month. AMCU is seeking to more than double this figure to 12,500 rand while NUM wants a 60 percent increase.