The Union Carbide Corp., responding to the urging of a federal judge, said today it was prepared to give an additional $5 million to the Indian government to aid the victims of the poison gas leak in Bhopal last December.

The company's pledge came two days after U.S. District Judge John F. Keenan asked Carbide to make an emergency payment of "$5-or-$10 million" to groups like the International Red Cross without its being considered an acknowledgement of liability for the Bhopal accident. Keenan said such a payment would be "a matter of fundamental human decency."

A Carbide lawyer responded at the time that it would be "possible" to make such a payment, but the company preferred to negotiate an overall settlement with the Indian government.

Today, however, Carbide Vice President Rolf H. Towe wrote Keenan that Carbide would make a $5 million payment to the Indian government if "it can be promptly and effectively made available to the victims of the disaster."

Asked why the company did not offer the full $10 million suggested by Keenan, Carbide spokesman Tom Failla said the company wanted to wait for a report requested by Keenan on the amount of aid already provided by the Indian government and the current medical and other needs of the people in the area.

"Let's see where this takes us; let's see what the needs are," said Failla. "We're seriously considering any needs that go beyond that."

In a separate report, Carbide said its first-quarter profits fell 34 percent, to $71 million ($1.01) from $107 million ($1.51) in the same three months of 1984 because of a drop in domestic and foreign sales. Sales for the latest quarter were $2.17 billion, down 9 percent from $2.39 billion.

A massive release of deadly methyl isocyanate leaked from a Carbide plant on Dec. 3, causing what has been described as the worst industrial accident in history. The Indian government has estimated at least 1,700 people died in the disaster and as many as 200,000 others were injured.

On Wednesday, Carbide lawyer Bud G. Holman challenged these figures, saying the company only accepts 1,408 "recorded" deaths at Bhopal and believes the number of injuries to be "a small fraction" of the government's 200,000. He said many of the injuries were only minor.

Asked today if in light of those remarks Carbide acknowledges that emergency relief funds are needed in Bhopal, Failla indicated it is unclear what the actual needs are. "I don't think we are acknowledging that" emergency relief funds are needed, he said. "We're saying, 'we share the court's concern.' "

Failla also said that the new pledge comes on top of $1 million the company provided last December to the Indian government for Bhopal relief and another $840,000 its Indian subsidiary offered to the state where Bhopal is located. The state government has not accepted those funds, however.

A spokesman at the Indian Embassy declined to comment on today's offer. Michael Ciresi, a lawyer who has filed suit against Carbide on behalf of the Indian government, said: "There has been a massive amount of aid that has been provided by the government of India. In comparison with what the government has done, this pales by comparison."