BP's strategy of quick growth and higher profits through acquisitions might have upset the company's safety procedures and helped cause recent high-profile accidents, experts said.
The international major was forced to cut output last week at Alaska's Prudhoe Bay, the largest US oil field, because of a leak in a badly corroded pipeline.
The event further tarnished BP's image, which had been hurt by a deadly 2005 Texas refinery explosion, said analysts, who added the company may have sacrificed some of its safety practices in its drive to expand.
"Mergers and acquisitions create an unsettled period that can diminish safety performance," according to a report by corporate culture consultants Vin Hoey and Harry McVeigh.
Safety priorities are often reshuffled as meetings, Web sites, and other communications focus on other topics during mergers, it added.
BP, formerly British Petroleum, dramatically increased its US footprint through a series of acquisitions. In the 1980s it bought the remainder of Sohio, formerly Standard Oil of Ohio, giving it access to the huge store of Alaskan crude in Prudhoe Bay.
In November 1998, BP shareholders approved the purchase of Amoco, which brought four of the five North American refineries it now owns, including the one in Texas City where 15 workers died on March 23, 2005.
On April 14, 2000, BP acquired Los Angeles-based Atlantic Richfield Company (ARCO) and on July 7, 2000, it completed a successful tender offer for Burmah Castrol of England.
"Merger or acquisition changes may not directly sow the seeds for poor safety, but they certainly disturb an organization and leave it vulnerable," Hoey and McVeigh said.
BP president Lord (John) Browne, who has overseen much of the company's expansion, has said he would take personal responsibility for the problems.
"The key to the response to each of the various challenges lies in the enduring values of the company and our ability to learn from mistakes, and includes learning from those who see that things are wrong and say so," Lord Browne said at a press conference held in Alaska last week.
Mega-mergers in the oil industry over the last ten years have created a new breed of energy giants, including "supermajors" Exxon Mobil and BP.
BP had been considered by bankers and analysts as one of the most effective in the industry in battling rampant inflation in oil field services costs.
Investors rewarded BP's efforts by boosting its share price to where it traded at a premium to most rivals.
Some analysts said BP's "management premium" slipped in tandem with its share price after the Prudhoe Bay leak.
Last week, Royal Dutch Shell overtook BP as the second-largest publicly-traded company by market capitalisation.
Now some analysts and investors are questioning whether BP's robust approach to cost management may have contributed to incidents it has suffered in the past two years.
"If you make some mistakes in how the management are compensated, or in management hiring, suddenly you've got a problem you didn't know you had," said Richard Lewis, a fund manager at New Star Asset Management.
BP's lack of regular maintenance on the Alaska pipeline is blamed for the corrosion and spill.
"They did all of these mergers and tried to show they were more efficient operators by cutting costs. Their own workers will tell you that their philosophy is to operate components and systems to failure," said Charles Hamel, a longtime critic of BP's Alaska operations.
BP's safety record has not gone unnoticed by the Department of Labor's Occupational Safety and Health Administration, which has made it a target of a program designed to monitor employers who defy safety and health regulations.
An OSHA inspection at the company's Toledo, Ohio, refinery found a number of violations similar to those that caused the deadly Texas City refinery blast a year earlier.
"It is extremely disappointing that BP Products failed to learn from the lessons of Texas City to assure their workers' safety and health," Edwin Foulke Jr, OSHA assistant secretary, said after the agency levied fines of $2.4 million against the Toledo refinery in April 2006.
BP is contesting the fines and a mediation hearing is scheduled for late August.