Cummins Inc posted higher-than-expected quarterly profit on Tuesday, lifted by strong sales of its vehicle components in North America, Europe and China. But the company, which also makes natural gas engines used to generate electricity, said global demand for that equipment “remains weak” and was considering a restructuring that could cuts costs in the long term but may reduce earnings by as much as $40 million. The Columbus, Indiana-based maker of diesel engines and fuel and emission controls reported third-quarter net profit of $423 million, or $2.32 a share, up from $355 million, or $1.90 a share, during the comparable quarter last year. Analysts, on average, expected Cummins to post a profit of $2.28 a share, according to Thomson Reuters I/B/E/S. Sales rose 15 percent to $4.9 billion. Revenue growth was especially strong in North America, where trucking companies, encouraged by the economic rebound, falling fuel prices and rising freight volumes, are updating their fleets and buying more trucks from key Cummins’ customers, including Paccar Inc and Navistar International Corp.