Seeking to reassure investors, Royal Dutch Shell on Tuesday said its $70 billion acquisition of the BG Group would allow it to realize $3.5 billion in savings, shed $30 billion in uncompetitive assets, and expand its operations in the fast-growing liquefied natural gas industry.

Although the British-based BG is only a midsize oil company, it is a major player in liquefied natural gas, known as L.N.G., which is becoming an increasingly popular alternative to other fossil fuels. The deal gives Shell a world-leading position in producing and trading L.N.G.

The company has been criticized for making a big acquisition at a time of low oil prices, but it is portraying the BG deal as an opportunity to streamline its own portfolio. Shell said it now expected to gain $3.5 billion in cost savings through job cuts, procurement savings and other operational efficiencies.

Shell, which hopes to complete the BG dealby early next year, said it would place its liquefied natural gas and related businesses into a separate unit called Integrated Gas.

The energy giant has invested heavily in L.N.G. in recent years — to the tune of about a third of its overall $200 billion in invested capital, including in a process called gas-to-liquids that converts natural gas into fuels like diesel and jet fuel.

A study by Oswald Clint of Bernstein Research in London concluded that with BG, “Shell will take the No. 1 spot in global L.N.G.,” with about 18 percent of the global market by 2020. The Persian Gulf emirate of Qatar would remain a bigger player than Shell, but its output is divided between two state-controlled companies, Qatargas and RasGas.

Mr. Clint estimated that Shell could add $1 billion ayear to its earnings through measures including sending L.N.G. to countries offering the highest prices.

As an indication of the increasing importance of liquefied gas to Shell, the company said that Maarten Wetselaar, who will head the new Integrated Gas unit, would join Shell’s executive committee, its top management rung.

Shell calculates that countries in Asia and other emerging markets will increasingly turn to gas, which burns cleaner than coal, as a fuel for generating power and for other uses. It is also betting that L.N.G., because it is not dependent on pipelines, will increasingly find markets in locales that have not traditionally burned natural gas.

Because BG holds undeveloped oil and gas properties in Brazil, East Africa and other areas, Shell, which has had lackluster exploration results, also says it can make large reductions in drilling and other exploration expenses. Previously, Shell had put the overall gains from BG at around $2.5 billion.

In other areas, Shell said it would cut back on North American shale activities, which have led to large write-downs at the company, and stop making new investment in tar sands projects.

The L.N.G. business is partly cushioned from the impact of lower oil prices because the fuel is usually sold on long-term contracts that are linked to oil with a delay of three to six months. Still, low prices cut Shell’s earnings from L.N.G. and related products in the third quarter to about $820 million, compared with $2.8 billion in the period a year earlier.

Over all, the company reported a loss of $7.4 billion for the third quarter. It took $7.9 billion in write-offs for operations including its recently halted exploration venture off Alaska and a Canadian heavy-oil project that it recently canceled.

“Low oil prices are driving significant changes in our industry; I am determined that Shell will be at the forefront of that and emerge as a more focused and more competitive company,” Ben van Beurden, Shell’s chief executive, said in a conference call with reporters on Tuesday.

^{Source: Reed, Stanley. "Shell to Focus on Liquefied Natural Gas in Deal for BG Group." The New York Times. The New York Times, 03 Nov. 2015. Web. 06 Nov. 2015. http://www.nytimes.com/2015/11/04/business/energy-environment/shell-bg-group-lng.html?_r=1.}