Undated (AP) _ Elated Filipinos living in the United States said they were pleased the Marcos regime fell ''without too much bloodshed,'' but warned that his successor, Corazon Aquino, faced a difficult job in uniting the Philippines.

Filipino groups in cities including New York, Chicago, Seattle and Los Angeles planned celebrations of the end of Ferdinand Marcos' 20-year reign.

But spokesmen for the estimated 2 million Filipinos living in this country also pressed for immediate release of political prisoners in their native land, calling it ''the first order of business'' for Mrs. Aquino.

And some expressed wariness that former associates of Marcos would continue to control the government.

''I'm very happy for my country and my countrymen. We did it in a peaceful, non-violent way. I think it is a reflection of our Filipino character,'' said Jun Mateo, a member of the Alliance for Philippine Democracy, a Los Angeles- based coalition of several anti-Marcos groups.

He said there would be a celebration at the Philippine consulate in the afternoon.

In New York City, Mila Manalac of the Coalition Against the Marcos Dictatorship said the group planned a celebration tonight.

''We're very, very excited and very happy,'' was all she would say immediately.

Noel Leyco, coordinator of the New York-based Alliance for Philippine Concerns, which he says includes about 30 groups around the country:

''We welcome Corazon Aquino and now that a new government is assuming power, we think the first order of business is to release all political prisoners jailed for fighting the dictatorship.''

He said greatest concern now of Filipinos here is that ''she's being installed by two former associates of Marcos. There is apprehension they may come to control the affairs of the government.''

''(I feel) relief that this whole thing has been settled without too much bloodshed and that it was settled relatively peacefully,'' Rodolfo Severino, Philippine consul to Houston, said in an interview with Houston radio station KIKK.

The diplomat said he feels ''compassion'' for Mrs. Aquino. ''She's got a very difficult job ahead of her,'' he said.

The Chicago-based Coalition for Philippine solidarity had already planned a rally and march today to protest U.S. intervention in the Philippines and to celebrate the Filipino people's efforts to dismantle the Marcos regime.

The Chicago area, with 120,000 people of Filipino ancestry, has the second- largest U.S. Filipino community.

''We, indeed, are grateful that Marcos has decided to leave the country,'' said Araceli Suzara, a 39-year-old Filipino native and a member of the coalition.

Jim Nolt, 28, an American with relatives in the Philippines and liaison member for the Philippine Support Committee, one of 10 groups in the Chicago coalition, also expressed wariness about the future.

''There's a certain amount of misgiving because some of the people who have taken over now have been closely aligned with Marcos for 20 years,'' he said. ''We're still going to be watching the human-rights situations in the Philippines very carefully.''

Dr. Luis Tan, a Phoenix, Ariz., pediatrician and a founder of the Filipino Club of Arizona, said the economy is Mrs. Aquino's biggest problem, and called on the United States to step up economic aid.

''The biggest need for the new administration is food and clothing for the poor. That's where the problem lies,'' he said.

In Petersburg, Ind., Honesto Fenol, a doctor who recently won a seven-year battle to stay in this country, said he hoped that the change in regime might enable him and his family to visit the Philippines.

''There's no question that there's no place like home,'' he said, ''but definitely just for a visit.''