Engineering support services group Redhall blamed substantial delays in securing work for a profit warning and said its Chief Executive was quitting.Redhall, which provides services to the oil & gas industry, said it had reviewed its forecasts and now expected 2013/14 results to be similar to those in the year to September 2013.The move followed more delays in the timing of major contracts and a more cautious assessment of the timing and impact of new business prospects, it said.Redhall also said Chief Executive Richard Shuttleworth had resigned and would leave immediately.It has appointed Group Commercial Director Phil Brierley as Group Chief Executive and Chris Kelly as Group Finance Director and Company Secretary.Redhall said its bankers HSBC were still fully supporting the group.Chairman David Jackson said: "The group continues to have a strong relationship with its key customers."Although the programmes of work from our major clients are suffering substantial delays, we are confident we will deliver our recovery plan albeit over an extended timeframe."The group is seeking to further broaden its customer base to reduce the reliance on existing major customers." Shares fell 10p or 25.6% to 29p by 15:33 in London. PW