Concessions proposed in the past few weeks by the companies to protect the exchange of competitively sensitive technical information between the merged units of the two companies have gone a long way toward easing concerns of regulators on both sides of the Atlantic, these officials said. European regulators are further along in their review, and already are circulating a draft agreement spelling out competitive safeguards required to obtain final approval.

Antitrust regulators at the European Commission and the US Federal Trade Commission had expressed concern about the potential anticompetitive impact of permitting Hughes, the world's largest maker of satellites and a publicly traded unit of General Motors Corp, to be purchased by Boeing, one of the leading providers of rockets that launch such satellites. In particular, antitrust officials scrutinised the transaction to determine whether the integration of satellite maker and rocket launcher would disadvantage rival rocket-launch companies including Lockheed Martin Corp of the US and Arianespace SA, a French-led European consortium.

In recent meetings, Boeing executives told European officials the company would erect strict informational barriers called firewalls between the satellite-making and rocket-launch businesses, to prevent the exchange of certain kinds of data. This offer is part of a draft agreement being circulated to some Boeing competitors, with a final decision expected within weeks. European Union and FTC officials declined to comment. Jim Albaugh, chief of Boeing's space and communications unit, recently confirmed that Boeing had submitted specific language to European officials and "we hope that language will be accepted." Boeing, the Seattle-based aerospace firm, announced the proposed acquisition in January.

At the time, Boeing officials expected to close the transaction by the end of June, but that timetable slipped as company executives worked to resolve the regulators' concerns. Antitrust officials at the FTC are focused on the same issues as their European counterparts, though they are likely to seek more precise remedies to ensure that Boeing doesn't gain an unfair advantage over rivals. No formal recommendation has been made to the agency's five-member commission. But FTC staff attorneys are considering requiring Boeing to immediately alert rival rocket companies and customers about design changes made to Hughes satellites that could affect the way they are launched.