Two studies released yesterday indicate that consumers are experiencing a smooth transition during the shift to competition in the telephone industry but that small businesses have suffered from increasing telephone charges since the Bell System breakup.

Bell Atlantic Corp., the regional holding company for Chesapeake & Potomac Telephone Co., yesterday said 828,000 customer telephone lines have been converted so far to give "equal access" to competing long-distance services.

The process, mandated by the divestiture agreement, eliminates the need for customers to dial lengthy codes to reach long-distance companies other than American Telephone & Telegraph Co. Equal access allows customers to switch from AT&T to another long-distance company without giving up easy, "Dial 1" access to long-distance service.

"This process is a rather involved one," said Marty Petrusky, assistant vice president of industry relations for Bell Atlantic. "We were the first to introduce it . . . and it has been hailed as a success by all those involved."

The company, which owns local telephone companies in New Jersey, Pennsylvania, Delaware, Maryland, Virginia and West Virginia as well as the District of Columbia, began converting telephone switching offices in July.

Bell Atlantic will have switched 44 percent of those lines in offices that can be converted to equal access by Sept. 1, 1985, exceeding divestiture agreement guidelines of 33 1/3 percent, Petrusky said. A total of 12 million telephone lines at 549 central offices will be converted by Sept. 1, 1986, Petrusky said.

Petrusky said the company's study showed that 70 percent of all customers notified by mailings 90 days in advance of equal access in their area read the material. Of those who read the material, 90 percent said they could make an intelligent choice about long-distance service. Customers who do not make a choice automatically default to AT&T.

Meanwhile, the House Small Business Committee yesterday said "access" charges that small businesses pay for the upkeep of the local telephone network should be dropped until the impact of the charges is analyzed more carefully.

A monthly charge of $6 a telephone line was imposed on small businesses last May by the Federal Communications Commission, which argued that the fee must be shifted away from long-distance company rates to discourage large business customers from bypassing the telephone company by building private networks.

"Small businesses with more than one line have really taken it on the chin," said Rep. Ron Wyden (D-Ore.), chairman of a special committee telephone task force. The access charges combined with local rate increases have left businesses with "new and unduly burdensome economic pressures," he said.

The committee issued a report saying that the FCC had not proved that imposing access charges is the best way of preventing large users from bypassing the phone company. Committee Chairman Parren J. Mitchell (D-Md.) said the FCC decision "can be undone by legislative action," although the panel has no current plans to introduce legislation to cancel the charges.