Chloride plugs into bid.
Bosses at the former battery manufacturer - now helping blue-chip firms to protect against power cuts - is recommending the offer from Zurich-based ABB.
The offer increases the pressure on rival Emerson Electric, which failed to win the company's support with a takeover proposal worth pounds 723m.
Chloride employs 2,300 people in 15 countries - with 374 based in the UK.
Power and automation specialist ABB said Chloride's strength proving uninterrupted power supply systems would give it a leading presence in a field where it is not presently active.
US-based Emerson Electric tabled its offer for Chloride in April - two years after it failed with a previous proposal. The US firm's latest offer was worth 275p a share against the 325p a share offered by ABB.