British engineer Invensys
The group said its operating profit for the year to end-March 2012 would be significantly below last year's 262 million pounds as a result of the operational issues.
The company, which also makes controls for washing machines, had been targeting an improved performance this year.
Shares in Invensys, which competes with ABB
They were trading 22 percent lower at 176 pence at 09:16 a.m. BT, the worse performing stock in the mid-cap index <.FTMC>.
Analysts said the warning raised questions about chief executive Wayne Edmunds, the group's former finance director who replaced Ulf Henriksson in the top job in March 2011, pledging an increased focus on execution.
Mark Wilson at Collins Stewart said: It has severely impacted my confidence in management's ability to deliver the promised margins from what has actually been quite a positive order intake.
Without that confidence it's difficult to be bullish on the shares.
Invensys said on Friday that delays and extra engineering in China would cost it an additional 40 million pounds, while additional costs in rail contracts would hit performance by about 20 million pounds.
Its appliance controls business was continuing to suffer from weak consumer demand in North America and Europe, it also said, although it was partially offset by stronger commercial and wholesale markets.
Invensys was formed from the merger of engineering businesses Siebe and BTR in 1999 in a deal that left the group saddled with debt.
In recent years it has turned to emerging markets, winning contracts in oil and gas, as well as rail signalling deals in Saudi Arabia and Turkey and nuclear power work in China, as demand in Western economies remained muted.
The push into new territory, however, had already hit margins in the rail business, with Edmunds saying in May that costs would rise as he invested in growth.
(Editing by Helen Massy-Beresford)