Senior executives at Delta Air Lines Inc. are giving serious consideration to following the lead of rival United Airlines in voluntarily installing enhanced cockpit-security barriers on certain jets, according to industry officials familiar with the airline's deliberations.

Delta hasn't made a formal decision, the industry officials said. But they added the carrier is considering installation of secondary barriers -- expandable, accordion-like gates designed to provide an extra layer of security by temporarily blocking access to the front section of the cabin just outside the cockpit door.

A Delta spokesman declined to comment.

United installed similar gates several years ago on most of the company's fleet of Boeing 757 jets. The move made the United Continental Holdings Inc. unit the only major U.S. carrier to take such a step, which it is extending to additional aircraft types.

Delta's deliberations come a decade after the Sep. 11 hijackings cast a spotlight on the dangers of cockpit intrusions and resulted in mandatory installation of stronger, bullet-proof cockpit doors on all U.S. airliners. The recent anniversary of those attacks heightened public concerns about commercial-aircraft safety.

A government-industry study group is set to issue technical guidelines next week spelling out the recommended strength and other characteristics of secondary cockpit barriers, capping three years of discussion and analysis. While not binding on carriers, the guidelines are expected to reassure Delta and other airlines contemplating such installations that they are following what amounts to industry-wide standards.

Once the guidelines become public, according to the industry officials, carriers won't have to worry about the prospect of making modifications or installing alternative systems, due to changing engineering or regulatory considerations.

Widely accepted technical specifications also could make airliner manufacturers, including Boeing Co., more inclined to offer barriers as optional equipment on future aircraft rolling off assembly lines.

For those airlines that "want to do something" in this area, the guidelines will "provide minimum performance levels" for barriers, according Margaret Jenny, president of RTCA Inc. of Washington, D.C., the nonprofit that works with regulators, airlines, manufacturers and others to develop consensus-based aviation policies and regulations.

The gates are intended to create a buffer zone between pilots and passengers when otherwise locked cockpit doors are temporarily opened in midair. Currently, flight attendants typically use catering carts or other techniques to set up a makeshift barrier when pilots, for instance, open the door to go to the bathroom; move to a crew rest area elsewhere on the plane; or leave or return to the cockpit for other reasons.

One of Delta's primary motives, according to industry officials, is to relieve flight attendants of those duties so they can pay more attention to passengers. In addition, the cabin layout of some aircraft models means that during the brief periods when makeshift barriers are used, passengers can't get access to bathrooms located at the front of the plane.

"A couple of carriers are looking at (installing) barriers from a customer-service standpoint," according to Ms. Jenny.

A spokesman for the Air Transport Association, which represents most U.S. passenger airlines, on Monday said the organization "supports the development of industry specifications for aircraft secondary barriers" in order "to ensure the highest possible level of safety."

Without going into details about the number or types of planes that already have secondary barriers, a United spokeswoman said "we continue to think this is important and make investments in the barriers."

Industry officials also said that the anticipated RTCA guidelines track the design of secondary barriers manufacturer Boeing is slated to offer as an option on its latest 787 Dreamliner models.

A Boeing spokeswoman said that while "there is no regulatory requirement for secondary barriers," the manufacturer does " offer a secondary barrier as an option on the 787" and continues "to study the idea with regard to other models."

A spokeswoman for the Federal Aviation Administration, which has no plans to mandate secondary barriers, didn't have any comment.