Peoples Drug Stores, Inc. and The Rouse Co. yesterday reported sharp increases in profits, while E. C. Ernst announced a large loss for its latest financial quarter.

Peoples reported a 51 percent increase in earnings for the quarter that ended July 2, posting profits of $3.0 million (39 cents a share), compared with $2.0 million profits (26 cents) earned during the same quarter last year. Sales climbed 16 percent for the same quarter to $184.2 million, compared with $158.8 million in 1982.

For the first three quarters of fiscal 1983, Peoples' profits increased by 31 percent to $9.9 million ($1.31) from $7.6 million ($1.01) earned during the first nine months of 1982. Total sales for 1983's first nine months totaled $607.5 million, up from last year's $525.6 million.

Meanwhile, Rouse reported a 36 percent increase in earnings before depreciation for the quarter that ended June 30, $8 million compared with last year's $5.9 million. Net earnings, after depreciation, totaled $2.8 million (19 cents), up from last year's $1.99 (13 cents) million. Revenues for the second quarter totaled $44.8 million, compared with $39.1 million last year. Rouse reports earnings before depreciation because it says its properties are appreciating in value, generally.

For the first half of 1983, earnings, before depreciation, totaled $15.2 million, up 35 percent from $11.2 million last year. Net earnings, after depreciation, for the first six months were $5.3 million (35 cents), up from $3.7 million (25 cents) last year, with revenues climbing from 1982's level of $76.5 million to $87.5 million.

Rouse said its retail centers maintained their good performance for the first six months of this year, earning $13.8 million before depreciation--a 23 percent increase.

Ernst reported a $2.4 million loss (61 cents) for the quarter ended June 30, compared with last year's $105,000 profit (3 cents) earned in the same quarter.

Contract income for the electrical construction and contracting firm increased 6 percent from $12.9 million during last year's quarter to $13.7 million. Ernst's chairman and chief executive, Joseph E. Griffin, attributed the net loss to cost overruns. Peoples, Rouse Gain; Ernst Has Loss

Peoples Drug Stores, Inc. and The Rouse Co. yesterday reported sharp increases in profits, while E. C. Ernst announced a large loss for its latest financial quarter.

Peoples reported a 51 percent increase in earnings for the quarter that ended July 2, posting profits of $3.0 million (39 cents a share), compared with $2.0 million profits (26 cents) earned during the same quarter last year. Sales climbed 16 percent for the same quarter to $184.2 million, compared with $158.8 million in 1982.

For the first three quarters of fiscal 1983, Peoples' profits increased by 31 percent to $9.9 million ($1.31) from $7.6 million ($1.01) earned during the first nine months of 1982. Total sales for 1983's first nine months totaled $607.5 million, up from last year's $525.6 million.

Meanwhile, Rouse reported a 36 percent increase in earnings before depreciation for the quarter that ended June 30, $8 million compared with last year's $5.9 million. Net earnings, after depreciation, totaled $2.8 million (19 cents), up from last year's $1.99 (13 cents) million. Revenues for the second quarter totaled $44.8 million, compared with $39.1 million last year. Rouse reports earnings before depreciation because it says its properties are appreciating in value, generally.

For the first half of 1983, earnings, before depreciation, totaled $15.2 million, up 35 percent from $11.2 million last year. Net earnings, after depreciation, for the first six months were $5.3 million (35 cents), up from $3.7 million (25 cents) last year, with revenues climbing from 1982's level of $76.5 million to $87.5 million.

Rouse said its retail centers maintained their good performance for the first six months of this year, earning $13.8 million before depreciation--a 23 percent increase.

Ernst reported a $2.4 million loss (61 cents) for the quarter ended June 30, compared with last year's $105,000 profit (3 cents) earned in the same quarter.

Contract income for the electrical construction and contracting firm increased 6 percent from $12.9 million during last year's quarter to $13.7 million. Ernst's chairman and chief executive, Joseph E. Griffin, attributed the net loss to cost overruns.