Updated 2:54 p.m.

A federal district judge for the District of Columbia has dismissed a Patton Boggs suit against Chevron Corp., ruling in favor of the oil company for the third time in four months.

U.S. District Judge Henry H. Kennedy, Jr. dismissed the Patton Boggs suit asking the court to declare the firm free from any ethical conflicts in its representation of Ecuadorian plaintiffs in a human rights matter against Chevron.

The potential for conflict arose over Patton Boggs’ ownership of the Breaux Lott Leadership Group, a lobbying firm that previously worked for Chevron. Patton Boggs represents the Lago Agrio plaintiffs in a suit against Chevron, represented by Gibson, Dunn & Crutcher. The suit in Ecuador is about contamination from petroleum drilling by Texaco Inc. in the 1970s and 1980s. Texaco was later bought by Chevron.

In November 2010, Patton Boggs filed papers in federal district court, asking for a declaratory judgment, absolving the firm of any conflict. That complaint was dismissed on April 19. Subsequently, Patton Boggs moved for reconsideration and sought to add new claims of tortuous interference. The motion was denied on July 8. Patton Boggs filed a similar complaint, amended to reflect the additional claims rejected in the reconsideration motion.

In his ruling, Kennedy wrote that “by neglecting to raise these arguments earlier, [Patton Boggs] simply failed to take proper advantage of that opportunity. That lapse does not entitle Patton Boggs to a second bite at the apple.”

He also warned Patton Boggs that “filing this action after the dismissal of its first suit, may have ‘unreasonably and vexatiously’ multiplied the proceedings before this court.” Kennedy chose not to require Patton Boggs to pay attorneys’ fees and expenses.

"This is the third time Judge Kennedy has rejected this baseless lawsuit and hopefully Patton Boggs will get the message and cease its frivolous campaign to deflect attention from its clients' fraudulent litigation against Chevron," Gibson partner Theodore Boutrous Jr., co-chair of the firm’s appellate and constitutional law group, said in a written statement.

Patton Boggs partner James E. Tyrell Jr., who is representing the Ecuadorians, said in a telephone interview that the firm filed an appeal to Kennedy’s first rulings on Friday and will likely file a notice of appeal on his most recent ruling.