Mikhail S. Gorbachev won Communist Party backing Friday for sweeping changes that would limit top officials to 10 years in office and create a new, stronger presidency he might fill.

The four-day national conference of 5,000 party members, the first since 1941, closed with Gorbachev proclaiming the reforms would point the way to a new "democratic image of socialism," and finding himself in the middle of an open feud between two top party officials.The confrontation between Kremlin No. 2 leader Yegor K. Ligachev and former Moscow party chief Boris N. Yeltsin, played out on Soviet television before millions of viewers, gave Soviets an unprecedented look at cracks in the monolithic front provided by Communist Party leaders.

Alexander Lukyanov, party Central Committee Secretary, told a late-night news conference the delegates backed Gorbachev's proposals to limit elected party officials to a maximum of two five-year terms with no exceptions.

He also said the new, stronger presidency backed by the conference provides the powers Gorbachev requested to settle matters of foreign policy and act as chairman of the Defense Council. The latter position traditionally is held by the party general secretary, the post Gorbachev has held since March 1985.

The conference also approved his recommendation that Communist Party leaders become the leaders of the corresponding legislature, all the way up to combining the job of president and party general secretary. That could set the stage for Gorbachev to consolidate his grip on power by taking on the more powerful presidency as well as being party chief.

Georgy Razumovsky, a non-voting Politburo member, said 209 delegates voted against that provision, an extremely rare show of dissent in the party.

Gorbachev, assessing the results of the conference just before it closed late Friday night, said, "Through democratization, economic reform and changes in the political system we will make perestroika irreversible. We will reach a fundamentally new state of our society, a new humane and democratic image of socialism."

He called the conference to pass judgment on his plans for perestroika, or restructuring of Soviet society.

Referring to his proposals to restructure the government's legislative branch and give the president new powers, Gorbachev said "the conference will continue living in the society, in the discussions in the society, but now we know how we must transform the political system."