Safeway Stores Inc. yesterday reported consolidated earnings of $27 million (44 cents a share) for the first quarter of 1986, a slight increase over the $25.7 million (43 cents) during the first 12 weeks of 1985.

Also yesterday, Bell Atlantic, the parent corporation of seven telephone operating companies in six mid-Atlantic states, including the Chesapeake & Potomac Telephone Cos. of the District, Maryland and Virginia, said its net income was $289.9 million ($1.45 a share) in the quarter ended March 31. That compared with profits of $255.3 million ($1.28) in the same period a year earlier.

American Express Co. reported its highest quarterly earnings ever, and Xerox Corp.'s first-quarter earnings showed a 31 percent increase over last year's first quarter.

Safeway said a federally mandated change in pension-fund accounting procedures resulted in an increase in net income of $4.7 million (8 cents) during this year's first quarter.

Safeway is one of the nation's largest processors, distributors and retailers of food.

Sales dipped 1.9 percent to $4.47 billion in the first quarter from $4.55 billion in the same period last year. The decline was attributed to disposal of several foreign operations last year.

But significant increases in foreign earnings were cited in the improved consolidated earnings.

*Bell Atlantic Corp., which is based in Philadelphia and serves about 27 million residential and business customers, said its first quarter revenue increased to $2.36 billion from $2.12 billion the previous year.

In a news release, Bell Atlantic said it planned to continue reducing the size of its work force and other expenses while attempting to increase volumes in several lines of business, including long distance calling and business access lines.

*American Express Co., citing "impressive" gains by two of its subsidiaries -- Shearson Lehman Bros. and IDS Financial Services -- yesterday reported the highest quarterly earnings in its history.

For the first quarter, American Express consolidated earnings increased 112 percent to $321 million ($1.40 a share) from $152 million (67 cents) in the same period of 1985.

The company said first-quarter revenue increased 37 percent to $3.6 billion from $2.6 billion in the year-ago quarter.

*Xerox Corp. yesterday reported first-quarter earnings of $101 million, down 11 percent from last year's $114 million.

Per-share earnings fell from $1.06 in last year's first period to 92 cents.

On a continuing-operations basis, total Xerox income declined 21 percent to $101 million from $127 million for the same period in 1985. Per-share earnings on a continuing basis fell to 92 cents from $1.20.

Xerox is based in Stamford, Conn.

*Three major chemical companies yesterday reported sigificant gains in their first-quarter earnings.

Dow Chemical Co. said its net income was up by 59 percent; Monsanto Co. said its earnings were up by 36 percent; and Hercules Inc. reported a 27 percent gain.

At its Midland, Mich., headquarters, Dow said it earned $175 million (92 cents a share) in the three months compared with $110 million (58 cents) in the year-ago period.

First-quarter sales totaled $2.85 billion, up 4 percent from $2.75 billion a year earlier, the company said.

Dow last year was the nation's second-largest chemical company by sales, ranking after E. I. du Pont de Nemours & Co.

In St. Louis, Monsanto reported first-quarter earnings of $118 million ($1.52) compared with $87 million ($1.12) a year ago.

Sales totaled $1.74 billion, as opposed to $1.62 billion in the same period of 1985, the company said.

In Wilmington, Del., Hercules yesterday said that it had a first-quarter net income of $45.4 million (81 cents) compared with $35.8 million (65 cents) in the same period a year ago.

Sales in the quarter grew to $645.2 million from $638.4 million a year ago, the company said.

*Lockheed Corp. yesterday reported first-quarter earnings of $87 million ($1.32 a share) compared with $84 million ($1.27) for the same period last year.

The aerospace and aeronautics company, which is based in Burbank, Calif., attributed its increased earnings to moderate sales growth during the first quarter.

First-quarter sales totaled $2.2 billion, compared with $2.1 billion for the same period last year, the company reported.

The increased sales boosted first-quarter profits to $163 million from the $156 million reported during the first quarter of 1985.

*Polaroid Corp., boosted by a 25 percent sales increase, yesterday reported a big earnings increase in the first quarter of 1986 compared with the same period last year.

Net earnings for the quarter were $16.1 million or 52 cents a share, compared with a loss of $13.8 million during the first quarter of 1986.

The company said last year's first quarter results included a pre-tax reserve of $309 million to cover Polaroid's selective voluntary severance plan. Without the reserve, net earnings would have been $4.2 million, or 14 cents a share.

I. MacAllister Booth, president and chief executive officer, said the company had a 30 percent increase in domestic sales and 18 percent increase in international sales. Booth said the profit jump stems from a combination of a weaker U.S. dollar -- which boosts exports -- higher sales and savings from cost-reduction programs.

The net after-tax foreign currency exchange gain in the first quarter amounted to 11 cents a share, compared with a gain of 1 cent a share in the first quarter of last year.

*Digital Equipment Corp. yesterday said that its fiscal third-quarter profit jumped 86 percent from a year earlier, while another major computer maker, Wang Laboratories Inc., posted a 26 percent gain in the latest quarter.

Burroughs Corp., however, said its profits tumbled 66 percent for the first three months of this year, and Texas Instruments Inc., a leading semiconductor maker that also produces computers, said it suffered a $23.8 million loss.

All of the companies said market conditions remained generally sluggish in computer and related industries.

Digital, the nation's second-largest computer maker behind International Business Machines Corp., said net income for its fiscal third quarter that ended March 29 climbed to $170.3 million ($1.32 a share) from $91.7 million (76 cents) a year earlier.

Revenue rose 14 percent to $1.93 billion from $1.69 billion.

Digital, based in Maynard, Mass., said the introduction of new computer systems earlier this year and the company's cost-cutting efforts helped lift revenue and earnings in the latest quarter.

Wang, which is based in Lowell, Mass., said its earnings improved even though domestic demand industrywide was "significantly lower" than a year ago.

Texas Instruments, which is based in Dallas, said "weak market conditions and severe pricing pressures in semiconductors" produced its latest quarterly loss despite continued cost-cutting efforts.

Burroughs, which based in Detroit, said its first-quarter profit skidded to $16 million (35 cents), from $46.6 million ($1.03) a year earlier. Revenue slipped to $1.14 billion from $1.17 billion.

*Burlington Industries yesterday reported sharply higher second-quarter earnings compared with the same period last year, despite lower sales.

Net earnings for the quarter, which ended March 29, were $19.9 million (70 cents a share) on sales of $679.8 million. During the same period in 1985, Burlington, which is based in Greensboro, N.C., reported net earnings of $5.1 million (18 cents) on sales of $709.1 million.

For the six months that ended March 29, net earnings were $28.3 million ($1.00) on sales of $1.4 billion compared with earnings of $9.7 million (34 cents) on sales of $1.4 billion during the same period in 1985.

*Philip Morris Cos. Inc., aided by a strong performance by General Foods Corp., which it acquired in 1985, yesterday reported record first-quarter earnings.

Philip Morris's consolidated earnings increased 23.3 percent to $316 million ($1.32 a share) from $256 million ($1.06) in the same period of 1985.

Consolidated operating revenue jumped 78.7 percent to $5.9 billion from $3.3 billion a year ago.

Philip Morris said General Food's operating revenue increased from last year's period and accounted for $2.4 billion of the company's total.