North Dakota's Public Service Commission may grant itself a second extension for deciding whether to allow construction of a new oil pipeline that would bring Canadian crude oil to Midwestern refineries.

The city of Fargo has made a late request to intervene in the pipeline siting case. During a brief PSC meeting on Wednesday, Commissioner Kevin Cramer said it is unlikely the commission will vote on whether to grant a permit before its self-imposed Dec. 12 deadline.

The pipeline's developer, TransCanada Corp., of Calgary, Alberta, wants to build the line through eastern North Dakota on its way south. It is designed to bring crude oil from Alberta to Illinois and Oklahoma.

The commission is holding another work session Monday to discuss whether to reopen hearings on the pipeline's location, and whether to allow Fargo to intervene. If the city is a formal participant, officials will be able to testify and cross-examine witnesses at any subsequent hearings.

Erik Johnson, Fargo's city attorney, said officials are concerned about potential oil leaks into the Sheyenne River and Lake Ashtabula, which the city relies on for drinking water.

The Public Service Commission had initially faced a Nov. 2 deadline for deciding on the pipeline permit. North Dakota law allows the commission to extend its deadline for "just cause," and the commissioners agreed earlier to set a Dec. 12 deadline.

In early October, Fargo Mayor Dennis Walaker asked the PSC to deny TransCanada a construction permit unless some environmental concerns were addressed, and Canadian authorities developed a more accepting attitude to North Dakota water projects.

Walaker's letter came weeks after public hearings on the pipeline's route had ended. Jeff Rauh, a Keystone spokesman, said the issues important to Fargo officials had been explored during public hearings that had already been held.

"The record is replete with information that addresses the very sorts of issues that are of concern here," he said. Both Rauh and Johnson attended Wednesday's PSC meeting.

Rauh said delays caused by the city's late entry into the pipeline debate could hold up pipeline construction and make the project more expensive.

"Those decisions to delay are imposing significant costs, and impacting our ability to meet the needs of U.S. customers for oil," he said.