United Mine Workers President Arnold Miller faces probable post-election challenges from both his rivals in last week's bitter UMW election.

Harry Patrick, who ran third in the three-way race, said Monday the election should be held again if an investigation confirms that Miller's forces deliberately delayed announcing a cutback in coal miners' medical benefits until the election.

The cutbacks were announced Monday. Patrick called for an investigation by the unions' executive board, charging that the decision had been made before the June 14 vote but was suppressed in a manner that "poisoned" the election outcome.

yesterday a spokesman for Lee Roy Patterson, who ran second in the race, said Patterson is "leaning" toward challenging Miller's election on other grounds, including ballot tigging.

Chuck Baker, a Patterson campaign aide, said Patterson is expected to decide whether to challenge the election sometime next week.

Patterson said during the campaign he would contest the vote if he lost, but Patrick's statement came as a surprise and could help Patterson if he decides to seek a new election. The union's executive board, which is dominated by pro-Patterson forces, has the power to overturn an election and order a new one.