Acting President Vladimir Putin's party made a surprise legislative deal with the Communists today that angered smaller, reform-minded factions previously sympathetic to Putin and prompted them to walk out of parliament in protest.

The lawmakers from three liberal and centrist groups complained that Putin's Unity party and the Communist faction had divided up the key leadership posts in the State Duma, the lower house of the Russian legislature.

Many political observers had predicted that Unity would ally with the three smaller liberal-centrist factions and displace the Communists as the chamber's dominant political force. Instead, Communist Gennady Seleznev was reelected speaker.

The turnabout raised questions about Putin's commitment to economic and social reforms, according to Russian political analysts. They said the bargain appeared to represent a departure from the policies of former president Boris Yeltsin, who stepped down and was succeeded by Putin on Dec. 31 and who had consistently battled the Communists. According to some reports, though, the Kremlin saw Seleznev as a pragmatist and relatively independent of Communist hard-liners.

About a fourth of the Duma's newly elected deputies joined the walkout. The dissenting legislators withdrew their candidates for speaker, boycotted the vote for a legislative leader and declined to accept any committee posts. One hundred legislators did not vote.

"This is a very serious defeat for Putin," said Andrei Piontkovsky, a well-known political analyst with the Center for Strategic Studies. "This makes a mockery of this talk about the great liberal who will introduce reforms. He could have made an alliance with the democratic factions, but he chose the Communists."

The discomfiting spectacle, in which one political leader after another stalked off the Duma floor, followed a speech in which Putin promised a "moderately liberal" economic policy and the pursuit of economic reforms. Apparently trying to reassure voters that he is not an autocrat at heart, he told reporters that Russia would never return to a dictatorship.

Just hours later, Putin's party made the deal with the Communists, who have opposed some of the reforms that Putin has endorsed.

Putin's appearance in the Duma chamber was a stylistic change; Yeltsin typically showed up only on the most momentous occasions. The acting president used the occasion principally to ask legislators to end the confrontations with the executive branch that were a regular feature of Yeltsin's era.

But just hours after Putin left, the session dissolved into a legislative brawl. The new Duma includes three former prime ministers--Sergei Kiriyenko, Yevgeny Primakov and Sergei Stepashin--plus former first deputy prime minister Boris Nemtsov. By late evening, all four had left the chamber in disgust.

Kiriyenko, Primakov and Nemtsov accused the Kremlin of conspiring with the Communists to control the Duma. Primakov, who heads the centrist Fatherland party, said he was withdrawing his candidacy for speaker because "what is happening here is a profanity."

"We are being dictated to and you can see it," he said.

Nemtsov, in a television interview, said, "What I saw today was beyond my imagination. . . . The Communists strike a deal with the Kremlin. . . . It is impossible to imagine a conspiracy between Yeltsin and the Communists even in the worst of nightmares."

How much political damage Putin sustained was not immediately clear. Ten weeks from the presidential election, his popularity continues to climb, despite setbacks in the war in the separatist region of Chechnya. In the most recent poll, taken last Sunday, 58 percent of respondents said they would vote for him.

His popularity and ability to tap the resources of the Kremlin have intimidated other potential contenders like Primakov, who is still mulling whether to run.

Putin is still an enigma, however, and his party's alliance with the Communists--even if only temporary--is likely to give some voters pause. Part of Putin's support comes from Russians who believe he will protect the country from a return to Communism, just as Yeltsin did.

The political turnabout was all the more surprising because many analysts predicted Putin would enjoy favorable relations with the Duma. While the Communists retained their position as the leading party with 24 percent of the Duma's seats, the December elections ushered in more centrist and reformist legislators.

Unity, a new party formed by the Kremlin and endorsed by Putin, captured the second strongest position in the Duma with 23 percent of the seats.

CAPTION: Liberal and centrist legislators leave Russia's lower house in protest.