Because a paragraph was inadvertently omitted from a RCA Corp. earnings article in yesterday's Business & Finance Section, the company's second-quarter results were incomplete. Although overall profits of RCA rose in the period to $85.6 million ($1.13 a share) from $78.3 million ($1.02) in the 1978 period, a one-time gain of $23 million from selling RCA Alaska Communucations Inc. was responsible for the higher quarterly earnings. Without this one-time gain, RCA's operating earnings were down 20 percent from the 1978 quarter. The headline in yesterday's edition - "RCA Profits Off Sharply" - referred to this decline in operating profits although final net income actually was higher.

Slumping NBC Television earnings, and a "substantial loss" at RCA Records sharply trimmed RCA Corp.'s second-quarter profits, RCA said yesterday.

The electronics, broadcasting, publishing and carental company said it earned $85.6 million ($1.13 a share) in the quarter, 9.3 percent higher than last year's $78.3 million ($1.02). Revenues climbed to $1.89 billion from $1.61 billion.

"Although NBC revenues continued to climb with strong advertiser demand for time, earnings fell as a result of lower ratings and heavy program costs," the company said. NBC ranks third in network ratings, behind CBS and ABC.

Two major bank holding companies reported substantial increases in earnings for the second quarter.

Bank America Corp., which owns the nation's largest bank, San Francisco-based Bank of America, reported income before securities transactions totaled $150 million in the quarter ended June 30, an increase of 26.8 percent from the second quarter of 1978, when earnings were $118 million.

Per-share earnings rose 27.2 percent from 81 cents in last year's quarter to $1.03 in the latest quarter.

President A. W Clausen attributed most of the earnings gain to growth in earning assets, particularly loans.

Chase Manhattan Corp., which owns the nation's third-largest bank, Chase Manhattan Bank of New York, reported income before securities transactions in the quarter ended June 30 totaled a record $80.3 million, up $33.2 million , or 70 percent, from the $47.1 million earned in the second quarter of 1978.

Per-share earnings for the latest quarter rose 79 percent to $2.34 from $1.31 in the second quarter of 1978, Chase said.

The bank holding company said the improvement stemmed form higher net interest income domestically and overseas, resulting from increased loan volume and higher interest rates.

Two of the nation's largest brokerage houses, Paine Webber Inc. and E. F. Hutton Group Inc., reported quarterly earnings declines yesterday, saying increased expenses offset higher revenues.

Hutton, the nation's second largest brokerage firm, said increased expenses, particularly high interest rates, had canceled out higher revenues from heavy securities business and left earnings for the quarter at $9.7 million($1.45 a share) compared with $11.3 million ($1.64) a year ago. Sales for the quarter rose to $177.8 million from $139.7 million.

In the first half of the year, Hutton profits were a record $14.7 million ($2.21) compared with $13.4 million from $235.5 million.

At Paine Webber, the nation's No. 4 brokerage firm, earnings for the third quarter ended June 30 were $4.6 million (77 cents a share) compared with $5.2 million (89 cents) a year ago. Revenues in the period, however, rose to $134.8 million from $110.5 million in 1978.

For the nine months ended June 30, Reynolds earnings were $7.9 million ($1.23) compared with $6.7 million ( $1) in the same nine-month period a year ago. Revenues rose to $361.7 million from $262.7 million.

United Technologies Corp. reported a 23 percent gain in earnings for the second quarter to $1.50 a share from $1.22 a year earlier.

Net income was $79.43 million on sales of $1.798 billion compared with $56.56 million a year ago on sales of $1.549 billion.

First-half profits were $150.27 million ($2.84 a share) on sales of $3.583 billion compared with $109.51 million ($2.36) a year ago on sale of $3.024 billion.

Burlington Northern attributed strong second-quarter earnings to brisker business and to lower costs resulting from extended winter weather that slowed work on BN's roadway improvement program.

BN reported earnings of $68.3 million ($5.26 a share), up 86 percent from $36.7 million in the second quarter of 1978.

Revenues increased 29 percent to $815.8 million from $630.2 million in the second quarter of 1978.

Time Inc. reported sharply higher second-quarter profits, largely on gains in its magazine publishing, television and paper-products divisions.

Time said it earned $42.3 million in the quarter, up 22.8 percent from $34.5 million before extraordinary items in last year's second quarter. Revenues rose to $629.6 million from $404.5 million a year ago.

Time's per-share income in the second quarter with 27.9 million shares outstanding, came to $1.52. A year ago, with 21.6 million shares outstanding, Times per-share income was $1.90.