Gov. Charles S. Robb signed Virginia's latest House of Delegates reapportionment plan in Richmond yesterday, then had it packaged for speedy hand-delivery to the Justice Department in Washington by a State Police trooper.

Scrutiny of the legislation--the sixth version of the legislative line-drawing measure in 13 months--will determine whether it meets antidiscrimination guidelines of the federal Voting Rights Act and therefore might be permitted to go into effect. Two earlier versions that reached the Justice Department were rejected, as was one challenged in U.S. District Court.

"I am relieved this is over," Robb said as he penned his name at the bottom of the bill. "I regret it was necessary to call the General Assembly back into session again" for its special meeting Thursday.

"I'm confident the assembly did everything required to meet the challenges posed to the plan," Robb added.

Attending the ceremony were House Speaker A.L. Philpott (D-Henry) and Attorney General Gerald Baliles.

In what was regarded as a victory for civil rights advocates, the legislators agreed to concentrate black residents in the Hampton Roads area into a handful of urban districts. The remapping would boost chances for electing two or three new black lawmakers this fall, adding to four black members in the state House and one in the Senate.