The director of the Virginia agency that enforces state coal mine safety laws owns nearly $19,000 worth of stock in the Pittston Co., the state's largest coal company and owner of the mine that exploded June 21, killing seven miners.

Before his appointment last year by Gov. Charles S. Robb to the post of chief mine inspector, Harry Dean Childress was employed for 10 years in management at the Clinchfield Coal Co., a division of Pittston. He was Clinchfield's assistant superintendent at McClure Mine No. 1, site of last month's accident, for nearly two years, from the summer of 1980 until May 1982.

During his years with the firm, Childress says he participated in employe stock ownership and saving investment plans under which he accumulated 1,162 shares of stock in Pittston.

A section of Virginia mining law states that "no mine inspector while in office shall be directly or indirectly interested as . . . stockholder" of any coal mine.

Childress said in an interview he has not sold his Pittston stock because he informed the state attorney general's office last year of his holdings and was told it did not constitute a conflict of interest under state law. He said he has remained in charge of the state's investigation of the McClure explosion.

"I could see how to somebody who doesn't know me it would appear that it would be a conflict of interest," he said. "But I don't really feel that it is. I'm loyal to whoever I'm working for at the time . . . . I still have friends at Pittston, but as far as allowing them to violate the law, I'm not going to do it."

Childress said today he was fully aware of the state's apparent prohibition on coal stock holdings by mine inspectors when he took office, but said he ignored it because of the advice of the attorney general's office.

"Why he ruled that way, I don't know," said Childress. "I'm no lawyer, I'm not an expert on the law. I go by what they told me."

State records show that the letter to Childress approving of his stock holdings last August was written by Senior Assistant Attorney General Francis Lee. He based his reasoning on the state's conflict-of-interest law, which then said that a state official had to own more than five per cent of a company's stock or receive income of at least $5,000 a year, excluding dividends and interest, to have a "material financial interest" that would pose a potential legal conflict.

Today Lee defended that letter, which made no mention of the separate mining law involving inspectors. He noted that while that law prohibits a "mine inspector" from holding coal stock, it makes no mention of the "chief mine inspector."

"I grant you that's kind of weird, but that's what the statute says," said Lee. "If it doesn't make any sense to you, it doesn't make any sense to me, either. But that's what it says and that's what we have to go on."

As chief mine inspector, Childress is the director of the state Division of Mines in Big Stone Gap, a 25-person agency that inspects all 624 coal mines in the state for any violations of state health and safety laws.

United Mine Workers officials, who have sharply criticized both federal and state enforcement at the McClure mine, said today that Childress ought to resign or be relieved of his duties if he continues to hold a financial interest in the coal industry.

"It just doesn't make any sense to me," said Joe Main, chief UMW safety administrator, when told by a reporter of Childress' stock holdings. "He should be relieved of that role without question . . . . As an ethical question, this casts doubt on his credibility to conduct his responsibilities and to enforce mine safety laws."

To UMW, the level of safety enforcement at the McClure mine is a central issue in the current state and federal investigation of the explosion. The mine, the union has said, is one of the state's most dangerous because of its unusually high levels of methane gas. Federal records show that the mine was cited for 163 violations of health and safety laws during the first nine months of this fiscal year.

UMW safety officials say they conducted their own inspection of the mine in April and found 51 safety violations, including buildups of explosive coal dust and other combustible materials in the section where the explosion occured. UMW officials say they warned federal officials at the time that the mine would "blow up" if the troubles weren't corrected.

Yet the UMW has charged, the U.S. Mine Safety and Health Administration (MSHA) did not increase inspections or enforcement actions. UMW officials said today that, if anything, state safety enforcement at the mine was weaker.

During the same month that UMW officials were conducting their inspection, Childress' office conducted a regular inspection at McClure and found nine violations of state law. None of them was considered an "imminent danger" or deemed serious enough to require a closure of any section of the mine, the only enforcement power state enforcement officials have.

"There's no way you could go through that mine during that time and find only nine violations," said UMW official Main. He noted that state records indicate a much higher level of violation notices at the mine last year, but that "after January of this year, it seemed to taper off."

"Inefficient, in one word," was the way Main described state inspections. "There was no tough enforcement by the state."

In two interviews, Childress defended state insepctions at the McClure mine and said that violation notices dropped this spring because safety there was improving.

"Our inspectors had felt the mine was in better shape," he said. "They were doing a better job of rock dusting to suppress the coal dust and cleaning."

Childress also emphasized that the precise cause of the June 21 explosion has yet to be identified.

"I feel we were doing the best job we could do . . . and I have confidence in my inspectors," Childress said.

Childress was appointed to the $35,000-a-year post of chief mine inspector last year by Robb after being recommended for the job by Blaine Carter, chief lobbyist for the Virginia Coal Association. A 31-year-old resident of Clintwood, in the far southwest corner of the state, Childress said he had been active in local Democratic party politics, made a contribution of less than $200 to Robb's 1981 gubernatorial campaign and accompanied Robb on a tour of the McClure mine during the campaign. A film of that tour, showing Childress and Robb together, was later used as part of a television campaign commercial that year.

After his tenure as assistant superintendent at the McClure mine last May, Childress worked briefly in Clinchfield's safety department under Monroe West, a former MSHA official who is now Clinchfield's top safety director.

UMW officials have strongly criticized West for harrassing MSHA inspectors at McClure and installing what the union contends is a potentially dangerous battery-charging station in a methane-contaminated portion of the mine. Childress declined to comment on the battery station, saying "I don't want to get in the middle of the controversy."

Childress acknowledged that he is a "friend" of West and meets and talks with him frequently, but said this would in no way interfere with his duties as chief investigator of the explosion. "I investigate Pittston and Clinchfield operators the same as I investigate any others."

A spokesman for Robb said today that the governor was not aware of Childress' stock holdings in Pittston at the time he appointed him, and did not comment further. Robb's Secretary of Commerce and Resources Betty Diener, who interviewed Childress for the job, said she was aware of the stock holdings, but was satisfied by the attorney general's opinion that they posed no legal problem.

"Harry is a professional, thorough and competent chief mine inspector," Diener said.