An obituary in Monday's editions of The Washington Post about George Rufus Brown, 84, a retired chairman of the Brown & Root construction company and an influential supporter of president Lyndon B. Johnson, failed to include the cause of his death. He died of a heart ailment.

George Rufus Brown, 84, a retired chairman of the Brown & Root construction conglomerate and an early supporter of the political ambitions of president Lyndon B. Johnson, died Jan. 22 at St. Luke's Episcopal Hospital in Houston, Tex.

The Brown & Root firm was founded by George Brown's brother, Herman Brown. He started the company when he was 21 years old with four mules and some road-building equipment he received in lieu of wages from a contractor who had gone broke. His first partner was his brother-in-law, Dan Root. His second was George Brown.

The Brown brothers wanted to build gigantic projects. Their first was the Marshall Ford Dam on the Colorado River in Blanco County, Tex. In 1937, the year he was first elected to Congress, Johnson ensured that this project, which was in the 10th Congressional District, the hill country, would be completed. This and subsequent government contracts over which Johnson had control enabled the Browns to build--and profit--on an enormous scale.

In return, the brothers pledged to the future president financial and political support that was available not only during his years in the Senate and the White House, but during his service in the House of Representatives, when he was searching for a way to make an impact on national affairs. In effect, the Browns and Johnson made each others' careers possible.

Moreover, the Browns persuaded other monied Texans to contribute where they contributed. According to Robert A. Caro, the author of "The Years of Lyndon Johnson: The Path to Power," Texas money thus became a major force in the country's politics. And the programs that rich Texans wanted--the oil depletion allowance is the best known, perhaps--became a part of the national political agenda.

Johnson was the channel through which this money flowed. In 1940, he raised thousands of dollars from the Browns and their friends and distributed it through the Democratic Congressional Campaign Committee to candidates facing tough elections in 1940. In Caro's view, this put the young Texan on the path to national influence. The power of Texas money, in turn, began to make itself evident far beyond the borders of the Lone Star state.

"We always believed in good government and keeping good people in office," George Brown once told an interviewer. "Those things go hand in hand. There's a place for both."

The Marshall Ford Dam was small compared to what came later. The Browns gambled everything they owned by starting to build it before it had even been authorized by Congress. By getting this approval and the necessary funding, Johnson brought not only wealth to the Browns but electricity to his impoverished constituents in the hill country. Caro describes this as the most important single benefit that a congressman ever has brought to his district.

In 1940, Brown & Root became the prime contractors on the giant Corpus Christi Naval Air Station, a $100 million undertaking. The company added shipbuilding to construction and during World War II did more than $350 million in work for the Navy.

From 1962 to 1965, the company built the $250 million Johnson Space Center in Houston. It pioneered in off-shore oil drilling. It built the 24-mile Lake Pontchartrain Causeway in Louisiana. It built military bases in Spain and France and other projects in the Middle East and Vietnam.

At his death, George Brown had a fortune estimated at $100 million. His donations to colleges, universities and cultural programs were on a commensurate scale and were estimated to have totaled almost $170 million.

The Browns were born in Belton, Tex. Their father was a hardware merchant. Herman began construction work when he was a boy. George graduated from the Colorado School of Mines and went to work for the Anaconda Copper Co. in Butte, Mont. He was badly injured in a mine cave-in and returned to Texas. In 1929, when Dan Root died, George became second-in-command of Brown & Root.

In 1962, when Herman Brown died, the company was sold to Halliburton Inc. George Brown became chairman of the board, a post he held until he retired in 1975. He remained active as a consultant and also in the direction of the Texas Eastern Corp., a natural gas company he had founded with his brother.

Mr. Brown's survivors include his wife, Alice; three daughters; 14 grandchildren, and seven great-grandchildren.