The $100 million rebuilding of the Parkington Shopping center in Arlington will be delayed at least six months, the developer, May Centers Inc., announced yesterday.

A spokesman blamed the setback on "architectural complexity" in planning the project and on red tape in arranging tax-free financing for a $25 million parking garage.

May also said it had picked yet another name for the project, which was known as Parkington for more than 20 years, then was dubbed Ballston Galleria a few months ago. The new shopping-office complex at Glebe Road and Wilson Boulevard -- atop the Ballston subway stop -- will be known as Ballston Common.

Both May Centers and Arlington County officials said the delays -- which would push opening of the renovated center back to the spring of 1985 -- are temporary.

"We are proceeding at full speed with the May Co.," said Thomas Parker, Arlington's director of development. The delay "in no way indicates weakened interest in May's plans to develop Ballston Common," said May Centers President Gregory Glass.

Parkington is the latest of several local office and retail developments to be delayed recently.

When the Arlington County Board approved the project in May, the chief objection was over the plan to build the garage using tax-exempt county revenue bonds to be repaid from parking fees.

May officials said they had been warned Internal Revenue Service approval of the move could take as long as six months.

The plan calls for refurbishing the present Parkington building and adding two 12-story office towers.