WASHINGTON.-Secretary of State William P. Rogers was reported today to have tried unsuccessfully to arrange a public hearing by the Senate Foreign Relations Committee that would, in effect, have publicized Pakistan's appeal for more assistance from the United States for economic development.

Mr. Rogers, according to trustworthy sources, telephoned Senator J. W. Fulbright Democrat of Arkansas, the committee chair man, yesterday to ask that he arrange a committee hearing for M. M. Ahmed, senior economics adviser to Gen. Agha Mohammad Yahya Khan, President of Pakistan. Mr. Ahmed arrived here Sunday from Islamabad and met President Nixon and Henry A. Kissinger, Assistant to the President for National Security Affairs, Monday at the White House.

Officials, meanwhile, discounted reports that Communist China had offered Pakistan an interest-free loan of $20- million not tied to the purchase of Chinese products. "China is spending about $200-million yearly helping North Vietnam," a financial official said. "It hasn't that much left over for Pakistan. It could never, for instance, pick up the entire $450-million yearly that Pakistan relies on from the 11-nation [western] consortium to keep going."

PAKISTAN SEEKS $70-MILLION

The United States has provided Pakistan with $4.5- billion in economic aid since 1954 and has contributed $200-million annually in recent years to an annual $450- million subsidiary granted to Pakistan by the 11-nation consortium, which is supervised by the World Bank. Pakistan is seeking $70-million in United States development loans before the fiscal year ends June 30. Mr. Rogers, who met with Mr. Ahmed yesterday, is also reported to have suggested to Mr. Ahmed that he go to Congress and also appear if possible on television to publicize Pakistan's plea that United States economic aid be resumed.

Senator Fulbright is reported to have rejected Mr. Roger's suggestion that the Foreign Relations Committee in effect serve as a sounding board for the Pakistani Government.

United States development aid to Pakistan has been suspended since March 25, when Pakistani troops were ordered to suppress a movement for political autonomy backed by the predominantly Bengali population of East Pakistan.

FULBRIGHT SEES DANGER

In rejecting Secretary Roger's suggestion that the Foreign Relations Committee help Mr. Ahmed's appeal for resumed aid, Senator Fulbright is said to have warned of a potentially dangerous trend.

There is a danger, he is said to have explained, that foreign statesmen of feuding factions within foreign governments might increasingly seek to win support by pitting the State Department and the White House against Congress.

"We don't always see eye to eye with the State Department," said one Congressional source, "but they're the people who should really be handling foreign visitors."

On the subject of supplying relief for East Pakistani civilians, Robert J. McCloskey State Department spokesman, said that the United States is hampered until invited by the Pakistani Government to participate in an international relief program. Secretary General Thant or the United Nation disclosed yesterday that President Yahya had declined a United Nation offer of aid but had hinted that it might be acceptable in the future.