The most recent rate increases requested by Chesapeake & Potomac Telephone Co. would raise residential and business rates in the District by 153 percent and 12.4 percent respectively, and in Maryland by 25 and 28 percent respectively.

The new District rate proposal, which would produce $75.8 million in additional revenue for the company, would separate charges for dial tone, or access to the system, and actual usage. Dial tone would cost a flat fee of $13.42. Users who now pay $12.49 monthly for unlimited local telephone calls would pay $15.40 for the same service under the new proposal, plus the $13.42 access charge.

Message-rate service, which gives users 60 calls a month for a flat fee of $6.38, would cost $15.77 -- $2.35 plus the $13.42 access fee. Service in D.C. only would rise from $6.38 to $23.11, including the access fee. Customers who now pay an "economy" rate of $3.11 per month plus 6.9 cents a call would pay $8.42 -- the only subscriber category to include dial-tone cost -- plus 13.7 cents per call.

The company's business customers in the District now pay $16.05 for 110 local calls a month, plus 6.9 cents for each additional call. The new proposal sets the rate at $10.91 a month for service alone, and 7.4 cents for every local call. Rates for additional lines would rise from $8.97 to $10.91.

The District proposal also would increase the coin-telephone charge from 15 to 25 cents and the charge for connecting a residential line from $25 to $52. The number of free information calls would drop from 10 to three a month, and the cost of directory calls would rise 3 cents, to 23 cents.

Repair fees for both classes of customers would increase from $21 to $22 for the first 15 minutes and from $11 to $11.50 for each additional 15 minutes.

Subscribers across the board would pay a 2.9 percent surcharge on Jan. 1, 1986, to compensate for the District's lack of revenue from intrastate calls, generating $6.8 million of the total increase.

In Maryland, where the increase would generate $123 million in additional revenue, usage and dial tone were separated earlier. But the dial-tone charge would rise between $4 and $5.

C&P of Maryland assigns residential and business customers to one of two rate categories depending on location. Dial-tone charges for customers in more heavily populated areas such as Baltimore and Silver Spring would rise from $5.40 to $9.56. Under the proposal, customers in those areas who currently pay $16.49 a month for unlimited calling thus would pay $20.65.

Message-rate service, which gives users 65 local calls for $9.20 a month, and so-called local measured service, which also costs $9.20 a month, would increase to $13.36 in those areas. Economy-service customers in high-population areas, who now pay $5.40, would pay $9.56. usiness customers in areas such as Baltimore and Silver Spring who opt for both message and local measured service would pay $14.76 for a dial tone, up from the current rate of $10.70.

Installation fees would rise from $18 to $32 for residential customers and from $27 to $32 for business customers, while telephone-ordering charges would rise from $19 to $22 for residences, and from $30 to $42 for businesses.

Additional business lines would cost $32 per month instead of the current $27. The cost of simple repair jobs for both types of customers would increase by $1 to $23 for the first 15 minutes. The rates would remain at current levels for the first 15 minutes of more complex repairs, but each additional 15 minutes would cost $12, up $1.

Coin-telephone charges would rise from 20 to 25 cents. It would cost 45 cents instead of 30 cents to verify a busy signal, but if line trouble were causing the signal, the call would be free. And asking the operator to interrupt a call between two parties would cost $1.20 instead of 80 cents.