UTC launched its unsolicited bid for Diebold in February with a $40.00 per share offer, which was 66% higher than the stock price at the time. Dieobold firmly rejected the offer, saying UTC's proposal significantly undervalued the company and failed to "reflect Diebold's strengths and significant upside potential".

The ATM vendor also spurned UTC's subsequent requests for management discussions and due diligence in connection with the bid.

Now UTC has released a letter to Diebold chairman John Lauer formally withdrawing the offer.

"We had hoped we could negotiate a transaction that would have created substantial value for both your and our shareholders," says UTC chairman George David in the letter. "It's unfortunate this won't happen."

However, in a separate statement Lauer says the Diebold board of directors is confident that the company is on track.

"The Diebold board of directors remains confident that the company is on the right path, and is encouraged by the continued improvement it has seen in the company's strategic initiatives to gain cost efficiencies and increase profitability," says Lauer. "Diebold is on-course for creating substantial shareholder value for its investors, despite current global financial market conditions."