The company confirmed yesterday that it was in discussions that could lead to an offer. One of the bidders is the New Jersey-based General Public Utilities. The other is rumoured to be Houston Industries of Texas, which bid unsuccessfully for Norweb last year.
The market has been expecting a bid since the Trade and Industry Secretary Ian Lang blocked an agreed pounds 1.95bn takeover of Midlands by the generator PowerGen 10 days ago. Within 48 hours the Midlands chairman Bryan Townsend had received a number of informal approaches from US utilities.
Other possible US suitors being mentioned yesterday included Pacificorp, Mission Energy, Duke Power and Florida Power and Light. There were also rumours of a possible counter bid by the water company Severn Trent.
Although Mr Lang has effectively blocked bids both by and for the two generators, National Power and PowerGen, the remaining independent regional electricity companies are all thought vulnerable to takeover.
General Public Utilities is capitalised at $3.8bn (pounds 2.5bn) and owns three utility companies on the US eastern-seaboard - Jersey Central Power and Light, Metropolitan Edison and Pennsylvania Electric. It has a turnover of just under $4bn and 10,000 employees.
Houston Industries is valued at $5.5bn and generates and supplies electricity to more than 1.5 million customers on the Gulf coast of Texas, making it the ninth largest electricity utility in the US. It also has international operations in Argentina and India.
Analysts speculated yesterday that a bid could value Midlands at up to 450p a share or more compared with its opening price yesterday of 385p. The shares closed 38p higher at 423p valuing the company at pounds 1.6bn.
PowerGen's attitude could be crucial to the outcome since it is sitting on a 21 per cent stake.