EMERSON Electric, the world's largest maker of power equipment for oil companies, has approached the Chloride Group about a takeover. The British supplier of batteries for sudden blackouts said it rejected an initial 657 million-pound (US$1.3 billion) offer.

Emerson proposed a cash offer on March 18, and the St Louis, Missouri-based company said yesterday it may make a further announcement if a formal offer is made.

Chloride said separately the 255-pence-a-share offer from an unidentified suitor undervalues it.

The purchase would bolster Emerson's Network Power division, its fastest growing unit, Bloomberg News said. Demand for equipment that protects hospitals, banks and airports from power failures helped boost second-quarter revenue at the unit by 28 percent to US$1.52 billion.

Chloride, based in London, climbed the most in 20 years in London trading yesterday. The shares touched a two-decade high and traded up 27 percent to 263.50 pence. Chloride has risen 49 percent this year, boosting the company's market value to 678.1 million pounds.

Chloride, which helps protect clients from power failures, boosted its order book to a record 100 million pounds in the first quarter, bolstered by clients in the IT, oil and gas industries.