MOSCOW (AP) _ A Communist disciplinary board on Thursday recommended the expulsion of Alexander N. Yakovlev, once was a contender to lead the party and until recently a top adviser to Mikhail S. Gorbachev.

The Central Control Commission accused Yakovlev of trying to split party ranks by supporting the Democratic Reform Movement, a new group he and prominent reformers like former Foreign Minister Eduard A. Shevardnadze created in July.

Yakovlev, 67, is considered the architect of Gorbachev's policy of glasnost, or openness. He was the Soviet leader's strategist and confidante on democratic reforms until he resigned in July. He had been thought to be a candidate for the top party job during a restructuring last year, but Gorbachev remained in charge.

His expulsion would be a major blow to Gorbachev, who has been struggling to weed out hard-liners, not fellow reformers. Gorbachev, party leader as well as president, could be forced into further political restructuring of the party as he faces open presidential elections next year.

Such changes are being espoused already by the newly elected chief of the party's Russian branch. Valentin Kuptsov, who replaced hard-liner Ivan Polozkov last month, told a weekly newspaper he was seeking to change the ''conservative'' nature of the Russian party and take a centrist position.

The Control Commission sent its recommendation for Yakovlev's expulsion to the policy-making Central Committee for further action, the state news agency Tass said.

Traditionally, party members are expelled by their colleagues in the factories or offices where they work. Since Yakovlev has worked for the Central Committee, its staff will vote on his case.

It is considered likely that the Central Committee will follow the Control Commission's recommendation.

The Control Commission acted after it received letters from party members complaining about Yakovlev's recent actions, Tass reported. The Commission also sought to expel Shevardnadze from the party, but he quit before it could do so.

When Yakovlev resigned from Gorbachev's staff, he said the reform movement remains open to members of any political party who support democracy and oppose dictatorship.

''The point is not to leave the party or to stay, but to make a collective effort against the wave of pronouncements and outcry from the sort of people who in the 1930s were responsible for the concentration camps and repressions in this country,'' he said last month.

A former Central Committee secretary and ambassador to Canada, Yakovlev was a member of the Communist Party's ruling body, the Politburo, until last year. At that time, party hard-liners were ascendant and Gorbachev backtracked on some reforms.

Last week, Russian Communist leaders voted to expel Russian Federation Vice President Alexander Rutskoi after he founded a pro-reform alternative to their hard-line branch and demanded it be recognized as the new, official Russian party.