American Broadcasting Cos., its television network bolstered by the broadcast of the Summer Olympics, said yesterday its third-quarter profits rose 47 percent from a year earlier.

In addition, Sears, Roebuck and Co. reported that its third-quarter consolidated net income rose 11.5 percent. Transworld Corp. and the Coca-Cola Co. also showed gains.

ABC reported improved earnings at its radio and publishing divisions, and the sports network ESPN recorded its first operating profit. Net income climbed to $46.7 million ($1.61 a share) from $31.8 million ($1.08) a year earlier, ABC said. Revenue jumped 64 percent to $1.08 billion from $659.6 million.

Chairman Leonard H. Goldenson and President Frederick S. Pierce said in a joint statement that the television network's profit was boosted by its coverage of the Summer Olympic Games in Los Angeles.

The broadcasting group's overall profit rose 40 percent from a year earlier on a 72 percent increase in revenue, ABC said. It noted, however, that expensive coverage of the political campaigns, especially the two conventions, cut into earnings.

The publishing division's profit rose 17 percent from a year earlier on a 9 percent rise in revenue and the Video Enterprises division cut its loss sharply, Goldenson said.

For the first nine months of 1984, ABC said net income rose 30 percent to $142.9 million ($4.91) from $110.3 million ($3.76) a year earlier. Revenue climbed to $2.77 billion from $2.08 billion.

Sears, Roebuck and Co. said its consolidated net income for the quarter was $321.9 million (88 cents), compared with $288.8 million (81 cents) in 1983.

Revenue rose 8 percent to $9.65 billion, compared with $8.93 billion for the same period last year, the company said.

For the nine months ended Sept. 30, consolidated net income rose 17.4 percent to $891.7 million ($2.47), compared with last year's $759.5 million ($2.15). Revenue increased 9.5 percent to $27.46 billion, compared with $25.07 billion in 1983.

Third-quarter income included a $60 million credit in the Allstate Insurance Group income tax provision, reflecting the reduction of deferred income taxes under the Tax Reform Act of 1984.

Net after-tax realized capital gains and other income totaled $28.3 million in the third quarter, compared with $4.7 million in 1983.

For the nine-month period, net after-tax realized capital gains and other income totaled $175.3 million, compared with $58.2 million last year.

Transworld Corp. yesterday reported a 76 percent gain in third-quarter net income in its third reporting period since it spun off Trans World Airlines.

For the third quarter ended Sept. 30, the food, lodging and real estate conglomerate reported net income of $36.6 million ($1.04) on sales of $511.4 million, compared with net income of $18.9 million (59 cents) on sales of $490.6 million a year ago.

Nine-month earnings included net income of $85.4 million ($2.39), compared with a loss of $55.7 million. Revenue rose to $1.48 billion, compared with $1.38 billion in 1983.

Chairman L. Edwin Smart said Transworld's food unit, Canteen Corp., continued to benefit from low inflation and a major rebound in its basic food service and vending operations. Spartan Food Systems, another unit, also reported improved results.

Smart said the company's hotel operations, Hilton International, showed improved profits but continued to be plagued by negative effects of the strong U.S. dollar.

Century 21, its real estate unit, showed lower results because of a 27 percent decline in transactions closed in the latest quarter. Smart blamed the slowdown on high interest rates.

The Coca-Cola Co. said third-quarter profits rose 16 percent from a year earlier on a 13 percent revenue gain.

Strong unit sales of soft drinks and "outstanding" profit growth at Coca-Cola's entertainment unit contributed to the improved results.

In the third quarter, net income climbed to $175.3 million ($1.34) from $151.6 million ($1.11) a year earlier. Third-quarter 1983 earnings came after a $689,000 loss from discontinued operations. Revenue rose to $2.07 billion from $1.83 billion.

Unit shipments of soft drinks in the United States rose 3 percent in the third quarter, with diet Coke and Sprite posting strong volume increases, said Chairman and Chief Executive Roberto C. Goizueta. Sales volume on international markets rose 4 percent, with sales in Japan and the Philippines leading the way, he said.

Goizueta said Coca-Cola's entertainment division, which includes Columbia Pictures Industries Inc., reported a "very significant advance" in operating income during the quarter. The increase resulted largely from the success of the movies "Ghostbusters" and "The Karate Kid" and the syndication of two television series, Goizueta said.

For the first nine months of 1984, net income jumped 15 percent to $498.4 million ($3.76) from $434.2 million ($3.19) a year earlier. Revenue gained 10 percent to $5.58 billion from $5.1 billion.