Mumbai: United Technologies Corporation has offered to acquire Diebold, one of the largest makers of automated teller machines and voting machines, for about $3 billion.

United Technologies, which first approached Diebold two years ago, initially made the unsolicited bid in private on Friday and later made it public.

The $40 a share cash offer by United Technologies values Diebold 66 per cent above its closing stock price of $24.12 on Friday.

The acquisition of Diebold would give United Technologies a chance to expand its electronic security business with one of the field's largest players.

United Technologies bought Initial Electronic Security Systems for about $1.2 billion last year.

Diebold has a strong presence in the ATM market in China, where United Technologies' Otis elevator business also is a strong contender in its category.

United Technologies' network of sales and maintenance for the elevators can be adapted to the ATM business, said James Geisler, United Technologies' vice president for finance and the head of its mergers and acquisitions team.

"This transaction creates significant and immediate value for Diebold shareholders with no operational risk, while creating long-term value for UTC shareholders," George David, United Technologies' chairman and chief executive, said in a statement.

Unted Technologies had on February 19 proposed talks with Diebold's board on a deal. Diebold, however, rejected any possible combination, saying a deal would not serve Diebold's interests and requested that United Technologies refrain from contacting its directors.