Navajo Chairman Peter MacDonald's bribery conviction disqualifies him from holding office for four years and throws Navajo politics into turmoil just weeks before the tribal election.

MacDonald, 61, was convicted in tribal court Wednesday of 41 counts of bribery, conspiracy and ethics violations for taking cash, loans, plane rides and use of a car from businessmen trying to curry favor with him.His son, Peter "Rocky" MacDonald Jr., 36, was convicted of 23 counts.

The elder MacDonald, who was suspended as tribal chairman last year, is seeking the new office of tribal president in the Nov. 6 election. His opponent is former tribal chairman Peterson Zah.

About 180,000 Navajos live on the 21,100-square-mile reservation in Arizona, Utah and New Mexico.

Navajo spokesman Duane Beyal said the tribe's nine-member election board was to meet Thursday to discuss the conviction. Officials declined to say if they might cancel the election.

Tribal law bars anyone convicted of ethics crimes from holding office for four years.

Prosecution and defense lawyers said they didn't immediately know how long a prison sentence MacDonald could get at sentencing Oct. 22. MacDonald, who was acquitted on one count, could have faced 211/2 years if convicted on all 42 counts.

His son could get up to 12 years in prison.

Attorneys for both men said they expected their clients would appeal.

The trial is the first of three scheduled in tribal court for MacDonald, a former aerospace engineer and four-term tribal chairman.

His second one is to begin Oct. 23 and involves conspiracy charges stemming from the tribe's purchase of a ranch for $33.4 million from a company that paid $26.2 million for the property only five minutes earlier. His son, an unemployed lawyer who lives in San Jose, Calif., is also a co-defendant.

The third trial, in which MacDonald faces 93 fraud counts stemming from the tribe's 1986 elections, is scheduled to begin Dec. 4.