<p>Foreign institutional investors, including sovereign wealth funds, are studying investments in the U.S. interstate oil and gas pipeline network as a way to obtain recurring returns in a low interest-rate environment.</p> <p>Dealmakers said they are advising funds, including from Asia, Australia and the Middle East, about potential investments that could bring billions of dollars of new capital to the sector.</p> <p>Other infrastructure areas also have attracted institutional investors. Drawn to the potential for steady long-term incomes, they have purchased stakes in companies operating toll roads, airports and utilities.</p> <p>Peter Bowden, co-head of energy investment banking at Jefferies Group LLC, said major pipelines with long-term contracts structured as take-or-pay deals from creditworthy shippers are most attractive to foreign buyers.</p>