The head of a conservative lobbying group has distributed a fund-raising letter that accuses two of the Maryland legislature's most fervent opponents of abortion of a "wholesale sellout of our families and children."

The letter, sent Dec. 30 to 7,000 Maryland residents by Family Protection Lobby head Jim Wright, chastizes Del. Timothy F. Maloney (D-Prince George's) and Sen. Francis X. Kelly (D-Baltimore County) for supporting a compromise program aimed at combating teen-age pregnancy.

The letter suggests that the legislative compromise forged by a gubernatorial task force and supported by 135 of 188 legislators would lead to the establishment of "comprehensive health care clinics in our junior high and high schools" and the dispensing of contraceptives to teen-agers.

The letter accuses Maloney and Kelly, along with Gov. Harry Hughes, of supporting a "safe-sex philosophy" and believing that the "best way to stop teen pregnancy is to teach kids how to have sex without becoming pregnant."

In an angry response sent today, Maloney and Kelly called Wright's letter "a repulsive attempt to solicit money for your organization by using distortions and outright lies to characterize the views of more than two-thirds" of the legislature.

The two legislators and the Family Protection Lobby in the past have been allies in fighting attempts to liberalize the state's policy of funding abortions for poor women. The dispute between them is the first evidence of dissention to a broad legislative consensus that seeks to avoid the annual divisive abortion battles by focusing on ways to prevent teen-age pregnancies and providing better health services to poor women who choose to have their babies.

In his letter soliciting contributions to the Family Protection Lobby to help defeat the proposals, Wright charged that "even our pro-life legislators have capitulated to Planned Parenthood's agenda."

In their reply, Maloney and Kelly said they do not advocate the establishment of school-based clinics and "strongly oppose any proposal to dispense contraceptives in the schools."

"Your letter," the lawmakers said, "has slanderous implications for the millions of Americans who deeply oppose abortion, but who do not object to contraception. If you attempt to limit the anti-abortion movement to those who also oppose contraception, then you will only be bringing serious harm to the pro-life cause."

Wright, the former head of the Maryland chapter of the Moral Majority, defended his charges, saying a letter from Maloney and Kelly to Hughes backing the compromise "expressly advocates confidential family planning in regard to minors. There is no way we are going to sit idly and watch that sort of a program forced down the throats of Maryland families."