British Nuclear Fuels (BNFL) is considering plans to sell its Westinghouse business in the US for $1bn (£548m), according to a report.
BNFL has to adapt to a changing landscape in the nuclear industry
The Times newspaper said that the disposal will be announced at the end of this month, but BNFL said no decision had been taken over the sale.
The state-owned firm is reviewing its operations after plans to privatise the entire business were shelved.
Westinghouse is a leading builder of nuclear power stations.
Cerberus Global Investments, a private equity firm chaired by former US Vice-President Dan Quayle, is thought to be interested in buying Westinghouse.
The sale would come as nuclear energy is making something of a comeback.
A growing number of scientists, energy industry observers and policymakers have been trumpeting the merits of nuclear energy as a safe and pollution-free way of generating power.
BNFL operates the Sellafield nuclear plant and the UK's remaining older Magnox stations.
Westinghouse, meanwhile, has been bidding for contracts to build new power stations in China and the US.
The Times quoted BNFL's chief executive Mike Parker as saying that "the UK government has been asking whether a new-build programme really fits with the risk profile it is seeking".
"It believes in the market; it doesn't want to own assets," he was quoted as saying.
Other interested companies could be French nuclear firm Areva and Louisiana-based Shaw Group.
Banking group NM Rothschild will oversee the sale of the Westinghouse, the paper said.
The role of BNFL is set to change with the creation of the Nuclear Decommissioning Authority (NDA) next year and it has shifted its clean-up activities into a separate company.
It will also transfer the majority of its assets and liabilities to the NDA.