Neither Williams nor Thorn EMI would confirm or deny the deal, which would strongly increase Williams' presence in the security industry, where it already owns Yale and Kidde.
According to one source, a deal could be announced soon. However, monopolies and other considerations might still stall it.
The price is unknown. The business has been hit by the slump in construction and recently announced an pounds 8m provision against bad debts and stock losses. But it could be worth pounds 100m free of debt.
Thorn Security was merged last year with Thorn's defence electronics business to form Thorn Security and Electronics. However, the two businesses could be separated again.
Williams was defeated last year in its hostile pounds 790m bid for Racal Electronics, which owns the Chubb locks business.Reuse content