LONDON (AFP) - KBR, a subsidiary of oil service giant Halliburton, is being investigated by Britain's Serious Fraud Office over the company's role in an alleged plot to pay bribes to win billions of dollars worth of contracts at a Nigerian oil plant, the Financial Times said.

For part of the period under investigation, Halliburton was headed by US Vice-President Dick Cheney, the newspaper reported.

The SFO said it had conducted searches at business and residential premises as part of its probe into KBR, which it said was opened in March, the latest in an investigation taking place in the US, France and Nigeria over an alleged plot to pay more than 170 million dollars (132.6 million euros) in bribes.

In response, Halliburton said it continued to co-operate and was "committed to getting resolution" but declined to comment any further.

The allegations came to the fore three years ago, when a former executive at the consortium working on the Nigerian gas plant told a French judge that it had run a slush fund to win contracts since the mid-1990s.

KBR owns a quarter of that consortium. British joint venture MW Kellogg own 55 percent of it, while energy giants Royal Dutch/Shell, Total and Eni, and the Nigerian government are also investors in the plant.

According to the Financial Times, more than 12 billion dollars has been invested into the plant, which cools natural gas into liquefied form so that it can be shipped.

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