The Washington Times said yesterday that it is sponsoring a worldwide fund-raising campaign to collect $14 million for the "contra" rebels in Nicaragua and has received a $100,000 commitment for the cause from the paper's owners, the Unification Church.

The Times campaign, coming just two weeks after the House rejected President Reagan's request for the same amount of aid to the contras, is among the most ambitious publicly announced initiatives so far to raise private money specifically for the anti-Sandinista guerrillas.

Arnaud de Borchgrave, the Times' editor, who has championed the contra cause on the paper's editorial page, announced in a front-page editorial yesterday that the newspaper is setting up a non-profit, public corporation that will oversee fund raising for the contras and that will operate independently of the paper's news operations.

The funds for the contras will go only for "humanitarian assistance" such as food, clothing and medical supplies, because federal law prohibits fund raising within the United States for weapons to be sent overseas, de Borchgrave said.

"This will be perfectly above-board, with no violation of any laws whatsoever," said de Borchgrave, who added that the drive is needed because "Congress is not willing to live up to its responsibilities.

"Unlike other papers, we are willing to put our money where our opinions are," de Borchgrave said.

The Times campaign was immediately welcomed yesterday by a Washington spokesman for the Nicaraguan Democratic Force (FDN), the largest of the rebel groups. FDN official Bosco Matamoros said the money for food and clothing would free up funds which the group can use "for other supplies."

"We have our people in the mountains who are struggling for Nicaragua . . . who are dying, who are suffering, who need this assistance," said Matamoros, who added that he personally called de Borchgrave yesterday to "express our gratitude for this effort."

De Borchgrave said he thought up the idea for the campaign on Sunday and won quick approval from Col. Bo Hi Pak, the top deputy to Unification Church leader Rev. Sun Myung Moon and president of News World Communications Inc., the parent company of the Times.

Pak "thought it was a great idea" and immediately pledged $100,000 to the drive, he said.

Since the editorial ran in yesterday's editions, "the phone has been ringing off the hook," de Borchgrave said. "I sleep in a couch in my office, and by 7 o'clock the calls started flowing in. People wanted to know where they can send the money."

The Times initiative comes while a number of closely related conservative groups such as the World Anti-Communist League (WACL) and the United States Council for World Freedom have been conducting independent fund-raising drives to funnel military and other aid to the contras.

Retired Army major general John K. Singlaub, the former chief of staff of U.S. forces in South Korea who heads both groups, said in a recent interview with Washington Post special correspondent Peter H. Stone that his group had raised almost $2 million outside the United States for arms for the rebels.

Adolfo Calero, political chief of the FDN, estimated that since Congress cut off aid to the contras last year, his group had received "close to $10 million" in private aid, about 40 percent of which he said was for arms and the rest for other forms of assistance.

But the full scale of private-sector aid to the contras has been difficult to determine, in part because many of the groups involved in raising money have described their efforts as being humanitarian aid to refugees in Honduras, where many of the families of Nicaraguan contras are living.

One such group that has acknowledged providing refugee assistance is Causa, the Unification Church's anti-Communist political arm that is also headed by Pak. Retired general E. David Woellner, Causa's director of world services, said yesterday that food, clothing and other supplies the group shipped to Honduras last year went only to "refugees and orphans. Maybe they became orphans because the Communists killed their fathers and mothers."

De Borchgrave said the Times campaign has nothing to do with Causa's efforts, adding that the newspaper plans to announce a list of distinguished individuals who will head up the nonprofit corporation later this week.

Referring to the huge financial losses the Times has suffered since it began publishing three years ago, de Borchgrave said, "People ask, how can the paper afford to do this when it isn't making money? The answer is that, on important moral issues, our corporate owners are willing to lend extraordinary assistance."

White House spokesman Dale Petroskey declined to comment on the Times campaign yesterday. Asked about private fund-raising for the contras in general, he said, "It's not something we encourage or discourage . . . We would like to see the Congress fund the effort."