Esmark, the giant meat-packing concern, yesterday reported lower first-quarter profits and blamed servere weather and the continued reduced margins in the commidity food businesses.

Esmark's chairman, Robert Renecker, told the annual meeting in Chicago that pre-tax profits were ahead of those in the third and fourt quarters of fiscal 1976, adding that "we see this as a signal of a return to more normal earnings levels."

Esmark reported earnings for the first quarter ended Jan. 29 of $14.8 million (80 cents a share), down from $20.7 million ($1.16) in the first quarter of 1976. Revenues declined from $1.37 billion to $1.25 billion.

Pepsi Co., Inc., the nation's second largest soft drink maker, yesterday said that its profits rose about 18 per cent in the fourth quarter and 27 per cent for all of 1976.

The company also proposed a 3-for-1 stock split and raised its quarterly divident from 50 to 60 cents a common share.

Fourth-quarter profits totaled $36.9 million ($1.50 a share) compared with $31.1 million ($1.27) a year earlier. Sales in the three months rose from $746.2 million to $835.5 million.

For the year, earnings rose from $107.5 million ($4.41) to $136 million ($5.56). Annual sales rose from $2.43 billion a year earlier to $2.73 billion.

"In a very competitive environment, we were able to achieve market-share gains in all the company's lines of business - particularly in domestic soft drinks and snack foods, where percentage volume increases were about double the industry average," chairman Donald Kendall said.

He said the stock split was intended to attract more individual investors to the company's stock.