Coca-Cola Co., the soft-drink giant that has interests in entertainment and foods, yesterday said first-quarter profits rose 14.2 percent on an 11.6 percent revenue gain.

Also yesterday, RCA Corp., parent company of prime time's No. 1 NBC, yesterday reported first quarter earnings of $73.4 million (77 cents a share), compared with $65 million (58 cents), in the same period of 1985.

AMR Corp.'s first-quarter earnings fell 93 percent because of fare wars that are ravaging the U.S. airline industry, the parent company of No. 2 American Airlines said yesterday.

And in other earnings reports, Merrill Lynch & Co. announced record revenue and sharply increased net income. Beatrice Companies Inc. said its fiscal 1986 net earnings were $232 million, down from $479 million in 1985. Union Pacific Corp. announced lower first-quarter profit and revenue, blaming the decline on tumbling oil prices.

W. R. Grace & Co. blamed an overall loss in the first quarter on its fertilizer operations and natural resources group. And Ameritech, one of the seven regional Bell holding companies formed from the breakup of American Telephone & Telegraph's Bell System in 1984, said in Chicago that its profits rose 4 percent on a 3.5 percent gain in revenue.

Conrail announced that its first-quarter net income rose to $60 million ($2.10 a share), compared with $55 million ($1.96) reported in the first period of 1985. However, revenue slipped to $775 million from $803 million for the same quarter last year.

Coca-Cola, which has proposed a 3-for-1 split of its common stock, to be effective June 16, said first-quarter net income rose to $161.2 million ($1.25 a share) from $141.2 million ($1.08) a year earlier. The year-ago results included a $1.3 million gain from discontinued operations.

First-quarter revenue climbed to $1.9 billion from $1.7 billion.

Operating income also was up in Coke's entertainment sector, which includes Columbia Pictures.

The board of directors will be asked to vote on the stock split at its meeting today.

*RCA Corp.'s sales in the first three months ended March 31 totaled a record $2.29 billion, compared with $2.07 billion a year ago.

RCA said its television network is leading the season-to-date standings for total audience in prime time, the primary reason behind NBC's record earnings and sales performance.

The record performance of RCA's aerospace and defense division reflected a $20 million U.S. Navy contract. The company said its consumer electronics division showed increased earnings partially as a result of higher pricing levels. And the gain in music and video sales reflected the merger with Ariola Records.

On Feb. 13, RCA shareholders approved a merger with General Electric Co. under which RCA will become a wholly owned subsidiary of GE.

*AMR Corp. said it earned $4.2 million (4 cents a share) in the first quarter, compared with $60.2 million ($1.07) in the comparable 1985 period. Revenue rose to $1.46 billion from $1.39 billion.

The airline's yield, the average amount of revenue received for every passenger flown one mile, dropped by 12.5 percent from the 1985 first quarter, the company said. Fares directly affect yields.

*Merrill Lynch & Co., citing strong financial markets, consumer demand for mutual funds and the record pace of corporate mergers and acquisitions, reported its net earnings for the first quarter rose 56 percent to $86.8 million from $55.6 million in the first quarter of 1985.

The firm had record revenue of $2.173 billion, a 37 percent increase over last year's $1.587 billion. On a per-share basis, earnings rose 47 percent to 85 cents from 58 cents last year. The results, which the company said are its highest in 10 quarters, reflect a $17.3 million charge for possible losses from the default of an overseas customer. No tax benefits relating to this charge have been recorded.

*Beatrice Companies Inc., which is scheduled to be acquired today by a New York investment banking company reported 1986 net sales of $11.4 billion, including businesses subsequently sold, compared with $11.9 billion the previous year. Excluding businesses sold through Feb. 28, Beatrice said, sales increased from $9.9 billion to $11.3 billion over 1985.

Net earnings were $2.11 a share in the fiscal year that ended Feb. 28, down from $5.06 in 1985, Beatrice said in a prepared statement. The company's fiscal year ended Feb. 28.

Beatrice said the closing is scheduled today for its previously approved $6.4 billion acquisition by Kohlberg Kravis Roberts & Co. and former Esmark chairman Donald P. Kelly.

*Union Pacific Corp. blamed its lower first-quarter profits and revenue on tumbling oil prices, which caused a 77 percent drop in earnings by the rail company's Champlin Petroleum unit.

The parent of Union Pacific Railroad, the country's third-largest rail network, said first-quarter net income fell to $103 million (88 cents a share) from $113 million (94 cents) a year earlier.

Revenue fell to $1.84 billion from $1.97 billion.

*W. R. Grace & Co., despite a strong performance by its specialty-chemicals business, yesterday blamed an overall loss in the first quarter on its fertilizer operations and natural resources group.

Grace reported a loss of $3.06 million (8 cents a share) compared with earnings of $35.07 million (67 cents) in the same period of 1985.

*Ameritech said its first-quarter net income rose to $284.7 million ($2.93) from $274.3 million ($2.80) in the year-ago period. Revenue climbed 3.5 percent to $2.29 billion from $2.21 billion.

Ameritech said revenue was up because of growing demand for local network services from Ameritech's Bell companies, and increased long-distance calling volumes.

Ameritech is the parent company of subsidiaries providing telephone service in Illinois, Indiana, Michigan, Ohio and Wisconsin.

*Conrail, based in Philadelphia, said traffic volume in the first quarter of 1986 was down about 1 percent when compared with the first quarter of 1985. Freight car loadings dropped to 700,000 in 1986 from 707,000 in 1985, and revenue-ton miles also declined.

"Conrail's first-quarter results continue to demonstrate our progress and stability as a company," said L. Stanley Crane, Conrail's chairman and chief executive officer.

"We now have a solid five-year-plus record of profitability, as well as improved, innovative service we provide to our customers as one of the best freight transportation companies in the country."