Alternatively, he could forward a final report to Congress and conclude his investigation.
It will take 9 to 12 months for the board to conclude its investigation and make its findings public, officials said.
"I have not yet concluded my investigation, but there is sufficient progress to warrant your attention."
During that time, the Italian authorities will try to conclude their investigation.
The commission must conclude its investigation into the proposed deal by April 7.
The safety board predicted it would take six to nine months to conclude its investigation of the collision.
The board is expected to conclude its investigation early next year.
The agency has been trying to conclude its investigation by the end of this summer.
"I believe," he said, "that concludes my investigation into the facts of this case."
And the commission has not yet concluded its antitrust investigation of Microsoft.