A CB&I Inc. acquisition of Baton Rouge’s Shaw Group Inc. will create a combined company with annual revenue of more than $11 billion, a project backlog of more than $28 billion and around 50,000 employees.

“We plan to create the most complete energy-focused, engineering services company in the world,” CB&I Chief Executive Officer Phillip K. Asherman said when the $3 billion acquisition was announced July 30.

CB&I, with its administrative offices in The Woodlands, Texas, will operate Shaw as a business unit called CB&I Shaw.

Here’s a brief look at the two companies’ histories and business operations, according to their websites and Advocate files.

THE SHAW GROUP INC.: Started as a pipe fabrication company, with headquarters in Baton Rouge. The company was formed in 1987 by J.M. Bernhard Jr., current chief executive officer, to acquire pipe fabrication assets of The Benjamin F. Shaw Co. in Laurens, S.C. It purchased and leased additional pipe fabrication facilities over the years and formed joint ventures overseas to produce pipe for projects in South America and the Mideast as it pursued joint ventures in the Far East, such as China. Shaw went public in December 1993 with 3,125,000 shares of common stock selling at $14.50 per share. Over the years, Shaw has acquired other companies like United Crafts Inc., Merit Industrial Constructors Inc., Badger Technologies and a drilling division of LFG&E International.

Shaw employs about 27,000 workers around the world, with 2011 annual revenue of $5.9 billion.

About 4,000 of its workers are in Louisiana, with 1,000 of those in Baton Rouge.

Its business segments include:

POWER: Shaw engineers, builds and maintains fossil-fuel and nuclear power plants. The segment also provides licensing support, management consulting, maintenance and modifications, emissions retrofits and decontamination and decommissioning services. Shaw is part of the AP1000 Consortium, which is building four nuclear reactors in China’s 30-reactor expansion program. Shaw has a plant in Lake Charles that makes nuclear reactor components. Shaw also owns a 20 percent stake in nuclear reactor maker Westinghouse, which will be sold in October to majority owner Toshiba, a move that helps clear the way for CB&I’s acquisition of Shaw.

Shaw does maintenance, plant engineering and turnaround services for more than 60 customers in the United States. The Power segment has a $9.2 billion backlog. The backlog for plant services is an additional $3.3 billion.

FABRICATION & MANUFACTURING: Shaw is the largest supplier of fabricated piping systems in the country and also supplies these systems worldwide. Shaw is considered a technological leader in the industry. Project backlog of $1 billion.

ENVIRONMENTAL & INFRASTRUCTURE: Shaw has decades of experience in design, engineering, consulting, construction and technology services for clients in the public and private sectors. Project backlog: $4.3 billion.

ENERGY & CHEMICALS: Shaw is selling this business unit for $300 million to Technip, a Paris offshore oil and gas exploration firm.

The Energy and Chemicals sale also helps Shaw meet one of the requirements for Shaw to be acquired by CB&I — having at least $800 million in cash. The unit provides engineering, procurement, construction and technology services.

The company researches, develops, designs and commercializes a wide range of refinery, petrochemical and chemical processing units.

Project backlog: $312.6 million.

CB&I: Founded in 1889 as Chicago Bridge & Iron Co. By 1997, when the firm went public with 12.5 million shares, it was headquartered in The Hague and concentrating on energy infrastructure projects. Nearly 80 percent of CB&I’s revenue now comes from projects outside the United States, and 90 percent of its business is tied to the oil and gas industry.

The company has three business segments:

LUMMUS TECHNOLOGY: CB&I acquired the company in 2007 for $950 million. It provides proprietary technologies critical to processing natural gas, petrochemical manufacturing and converting crude oil into consumer products, such as gasoline and diesel. Lummus has more than 70 licensed technologies and 8,200 patents and patent applications.

PROJECT ENGINEERING AND CONSTRUCTION: CB&I has more than 50 years of experience in the liquefied natural gas industry.

The segment has engineering and built some of the largest infrastructure energy projects on Earth, including LNG regasification and liquefaction terminals, refinery projects and petrochemical complexes.

STEEL PLATE STRUCTURES: CB&I is the world’s largest tank construction company. The segment has engineered and built storage and containment vessels for the petroleum, water and nuclear industries. CB&I has built more than 46,000 tanks in more than 100 countries.