A cable television lobbying organization has accused the Sinclair Broadcasting Group of withholding more than 200 documents and other materials from the Federal Communications Counsel during the agency’s investigation of its proposed merger with Tribune Media.

In a letter obtained by The Desk on Thursday, the American Cable Association’s (ACA) lead counsel Ross Lieberman charged Sinclair with withholding “more than 250 agreements, schedules, exhibits, and related documents,” including information on the company’s planned divestiture of some Tribune stations in order to obtain FCC approval of the proposed $3.9 billion merger.

The letter was prompted by a recent amended filed by Sinclair with the FCC over an issue involving several stations that the company wants to sell if the Tribune deal closes. The issues include the sale of St. Louis-based CW affiliate KPLR (Channel 11), which Sinclair planned to sell to the Meredith Corporation. That sale was canceled after the Justice Department raised concerns that the sale of KPLR to Meredith, which already owns CBS affiliate KMOV-TV (Channel 4), would create unfair competition in the St. Louis market.

Sinclair now says it wants to sell KPLR to an unknown third party. A report said Meredith is currently working with the Justice Department to determine how it might acquire KPLR once the station’s ownership is transferred.

Lieberman wrote that Sinclair has not fully disclosed information that would shed light on the types of discussions the company has had with the companies it wants to sell the excess stations to if the Tribune deal is allowed to go through. That’s problematic, Lieberman wrote, in part because the merger would allow Sinclair to become one of the largest broadcasters in the country.

“The Commission cannot allow Sinclair to hide the ball in this manner,” Lieberman said. “Not in a merger of this magnitude, not with a part that the Commission recently found to have abused its relationships with other broadcasters, and not where, as here, the genuineness of divestitures is so important.”

Sinclair has been accused by some of attempting to exploit newly-relaxed broadcast rules imposed by the FCC, including its reliance on the recently-reinstated UHF discount which allows broadcast companies to circumvent some rules that limit how many stations a company may own.

The ACA takes those accusations one step further by accusing Sinclair of attempting to have some control of certain stations even once they are sold to other companies. Lieberman says some of the documents withheld from the FCC “appear to contemplate an ongoing commercial relationship between Sinclair” and the companies that the stations are sold to.

“No one knows what arrangements have been reached in any of these documents, and Sinclair has unilaterally decided the Commission need not review them,” Lieberman wrote. “In the end, the Commission must determine that Sinclair’s divestitures are genuine beforeit can approve this transaction. This is particularly important here because Sinclair has claimed its place as the poster child for abusing such arrangements.”

Last month, Sinclair announced it would sell a number of Tribune-owned Fox affiliates, including stations in Seattle, Sacramento, Denver and San Diego, if the merger was given FCC approval. The sell-off was an attempt to ease some of the agency’s scrutiny over the deal. Last week, the FCC said it was extending its deadline for public comments on the matter to July 12.

A Sinclair Broadcasting spokesperson did not return a request for comment.