Two of three mercenaries accused of plotting to overthrow the tiny republic of Dominica in the Caribbean were found guilty today of conspiracy and violation of the Neutrality Act.

A jury of seven women and five men deliberated more than 11 hours before returning guilty verdicts against Stephen Don Black, a 28-year-old Ku Klux Klan leader from Birmingham, Ala., and Joe Daniel Hawkins, 37, a longtime Klansman from Jackson, Miss. Both were found not guilty of violating five firearms statutes.

The third defendant, Michael Norris, 21, a former Klansman from Northport, Ala., was found not guilty on all counts. Mr. Black and Mr. Hawkins could be sentenced to a maximum of eight years in prison and could be fined $13,000. The jury received the case yesterday and spent nine hours going over evidence before recessing for the night. Federal District Judge Lansing L. Mitchell ordered the jury sequestered.

In his instructions to the jury before the start of deliberations, Judge Mitchell said it should not to be influenced by the guilty pleas of seven of the defendants' comrades.