Albertson's Inc. said sales for the 13 weeks ended July 28 were $1.66 billion, an increase of 12.1 percent over the $1.48 billion for the same quarter last year.

During the period, identical store sales increased 4.5 percent. Earnings for the second quarter increased 28.5 percent to $37.1 million, or 56 cents per share, compared to $28.9 million, or 43 cents per share, last year.Sales for the 26-week period were $3.21 billion, an increase of 11.6 percent over the $2.88 billion for the like period last year. Earnings were $72.5 million, an increase of 25.1 percent over the $58 million for the like period last year. Earnings per share were $1.09 compared to 87 cents for the first half last year.

For the 26 weeks, gross margin was 22.2 percent compared to 22.4 percent for the quarter last year.

"We are very pleased with the results for the first six months," said Chairman Warren E. McCain. "The company is positioned well to continue its aggressive expansion program . . . With these results we have a good foundation to make 1988 our 19th consecutive year of increased sales and earnings."