The deal that will create a new powerhouse in Christian publishing is still being finalized more than a month after the expected completion date.

When HarperCollins announced its acquisition of Thomas Nelson in October—a move that will make Nelson a division alongside long-time rival Zondervan—the purchase was said to be set to be finalized by the end of 2011.

HarperCollins' Vice President of Corporate Communications Erin Crum told Christian Retailing this week that the company had “no information on a definite date for the acquisition to be finalized.” The regulatory review period was continuing, she added, “but we expect the review will be concluded in due course.”

Crum said that the original closing date had been only an estimate given by the two parties “and going beyond the end of 2011 should not be taken as any indication of how the review process is going.”

While details of HarperCollins' future plans have not been disclosed, the company has said that Zondervan and Nelson will continue as separate entities. Some consolidation is expected as a result of the deal, which will make HarperCollins a dominant book publisher and the major Bible publisher.

As the acquisition process continues, Nelson has marked a record with the highest number of titles ever (11) on various New York Times bestseller lists in a single week. With six titles spread across seven categories in the Jan. 22 listings, the company held more positions than all other Christian publishers combined.

Among the successes was Real Marriage by debut Nelson authors Mark and Grace Driscoll, which reached the No. 1 spot on the “Advice, How-To and Miscellaneous” list after releasing Jan. 3. Heaven is for Real by Todd Burpo with Lynn Vincent has appeared on the list for a total of 62 weeks overall. The book was also recognized as Nielsen’s 2011 “Adult Non-Fiction Book of The Year.”

Other Nelson titles on the Jan. 22 list included Nearing Home by Billy Graham and How Do You Kill 11 Million People? by Andy Andrews.

The achievement “demonstrates the impact of strategic publishing, focused effort and teamwork with our authors and retailers,” said Nelson President and CEO Mark Schoenwald. “Our products have consistently appeared on multiple best seller lists, both in the secular and the Christian market, but never to this extent.  We are excited by these results as we work to fulfill our mission to inspire the world.”