U.S. antitrust officials aren’t satisfied with Halliburton Co.’s proposals for clearing its purchase of oil services rival Baker Hughes Inc. and don’t expect to make a decision until next year, according to a person familiar with the situation.

The companies previously agreed to an extension until Tuesday with the Justice Department over the proposed $26 billion merger. The U.S. antitrust officials aren’t obligated to complete their review by today, said the person, who declined to be named because the review is confidential.

The companies can’t close their deal because antitrust officials in Europe, Australia and Brazil are also reviewing how the merger of the world’s No. 2 and No. 3 oil-servicing companies could change the competitive landscape.

Halliburton spokeswoman Emily Mir and Melanie Kania, a spokeswoman for Baker Hughes, declined to comment.

Halliburton fell 2.9 percent and Baker Hughes fell as much as 1.5 percent on the news. Halliburton recovered and was trading up 2.6 percent at $37.50, while Baker Hughes gained 5.3 percent to $49.27 at 12:35 p.m. in New York.

The combination has been fraught from the beginning. The companies faced early resistance from U.S. officials, who were concerned the tie-up could hurt competition because it would reduce the top three players to two, a person familiar with the matter told Bloomberg News in July. The officials were concerned even then that the oilfield services industry would become too concentrated and that proposed asset sales didn’t go far enough, the person said.

In November, the company sought European approval for the takeover a second time, four months after regulators rejected an earlier filing on the bid. The initial deadline for that review is Jan. 12. The EU may still opt to open an in-depth probe lasting about four months if remedies fail to allay competition concerns. Australia’s competition watchdog has also queried the transaction, and delayed its decision until Dec. 17 after asking for more comments from market participants.