PITTSBURGH — Republican state Sen. Jane Orie will stand trial alone on campaign corruption and related charges this month, and her sister Janine Orie will face a separate, still-to-be-scheduled trial, a judge ruled today.

The retrial scheduled to begin Feb. 27 for both sisters resulted from a mistrial declared by Allegheny County Judge Jeffrey Manning, who believed at least one defense document submitted by the senator was forged during the original trial last year.

Sen. Orie, 50, and Janine Orie, 57, remain charged with directing the senator’s paid staff to do campaign work on state time that benefited the senator and a third sister, Supreme Court Justice Joan Orie Melvin, for the past decade.

Since then, Allegheny County prosecutors have filed forgery, perjury and other charges against the senator.

In December, prosecutors filed additional charges against Janine Orie, accusing her of directing Justice Melvin’s former Superior Court staff to do campaign work on Melvin’s unsuccessful Supreme Court run in 2003 and her successful 2009 campaign.

Janine Orie’s attorney, James DePasquale, had argued there was a danger that she could be found guilty by association if the retrial included testimony about Sen. Orie’s alleged perjury/forgery cover-up, which is why he wanted separate retrials for the sisters.

Manning agreed.

It was not immediately clear when Janine Orie will be tried.

Although Sen. Orie and Janine Orie are both accused of misusing state-paid staff to benefit Melvin, the justice has not been charged — though her attorney acknowledged last year that she was being investigated by the same grand jury that charged her sisters. Melvin’s attorney, J. Alan Johnson, a former federal prosecutor, was in court Tuesday but declined to comment.