(Reuters) - Alphabet's Google must face trial on U.S. antitrust enforcers' claim that the internet search juggernaut illegally dominates the online advertising technology market, a federal judge ruled on Friday.

U.S. District Judge Leonie Brinkema in Alexandria, Virginia, denied Google's motion during a hearing, according to court records.

Google had argued for a win without a trial, saying that antitrust laws do not block companies from refusing to deal with rivals and that regulators had not accurately defined the ad tech market.

Court papers did not specify what reasons the judge provided at the hearing. Motions like the one Google filed are only granted where a judge determines there is no factual dispute to send to trial.

Brinkema is scheduled to preside over trial in the case on Sept. 9.

"We look forward to setting the record straight," a spokesperson for Google said.

A Justice Department spokesperson declined to comment.

The Justice Department and a coalition of states sued the tech giant last year, claiming it was unlawfully monopolizing digital advertising and overcharging users. The lawsuit seeks primarily to break up Google's digital advertising business to allow for more competition.

The regulators convinced Brinkema on Friday to block a former FBI agent who acted as a cybersecurity consultant for Google from testifying as an expert at the trial.

Google notched a win in the case last week when Brinkema allowed the trial to go forward without a jury, after the company settled claims that its conduct harmed the U.S. government.