Labor Secretary Ray Marshall said yesterday the government is looking into recent renewal of an insurance contract between a Teamsters health fund and a businessman convicted five years ago of conspiring to defraud a Teamsters pension fund.

In response to reporters' questions, Marshall said he is "concerned" about Allen M. Dorfman's winning a 10-year insurance contract extension July 19 from the trustees of the Teamsters' Central States Health and Welfare Fund.

He would not say whether the Labor Department might try to block the award but said the Dorfman contract would be a target of the department's newly launched probe of the health fund.

He would not say whether the Labor Department might try to block the award but said the Dorfman contract would be a target of the department's newly launched probe of the health fund.

A recent departmental investigation of the separate pension fund resulted in resignation of Teamsters President Frank Fitzsimmons as a trustee and transfer of the funds assets to outside managers.

Dorfman has been involved with the pension and health funds since the 1950s and one of his firms currently services the processing of claims for the health fund. In 1972 he was convicted of conspiring to accept a kickback to facilitate the granting of a loan from the pension fund.

Marshall said he was not prejudging the propriety of the Dorfman contract but would not consider it a "fait accompli" if it was unsound or illegal.

Marshall also announced that the department has filled 105,000 new public service jobs under the administration's economic stimulus program. It is well ahead of schedule in meeting its goal of 725,000 such jobs - more than 400,000 of them new - by February, 1978, according to the secretary.

A total of 403,000 persons are at work on these state and local government jobs, ranging from blood-pressure screening in Gary, Ind., to flood control work in Alpine, Tex., Marshall said.

At this rate, the department will meet its 725,000 goal by Dec. 31, he said.

Assistant Secretary Ernest G. Green said 27 per cent of the new jobholders are welfare recipients and the average wage is $3.50 to $3.60 an hour, well above the minimum wage of $2.30.