Semi trucks and trailers go together like hot dogs and buns.

But a longtime Indianapolis-based Peterbilt dealer that until recently sold both trucks and trailers is having a hard time unloading the trailer side of the dealership.

Steve Riddle, who last year sold the Peterbilt part of Utility-Peterbilt, is battling California-based Utility Trailer Manufacturing Co. for allegedly blocking the sale of the dealership’s trailer sales arm, known as Utility Trailers of Indianapolis, or UTI.

Riddle’s UTI alleges intentional interference with a contract in a lawsuit filed against Utility Trailer Manufacturing last month in U.S. District Court for the Southern District of Indiana.

Joining UTI as plaintiff is Peterbilt of Indiana, a unit of Wisconsin-based JX Enterprises Inc., which acquired Riddle’s truck-sales business late last year for an undisclosed price.

The former Utility-Peterbilt, 4225 S. Harding, now operates as JX Peterbilt Indianapolis.

Peterbilt of Indiana is also under contract to pay more than $1 million for UTI, the trailer sales arm of the former Utility-Peterbilt, according to court records.

But California trailer maker Utility Trailer effectively has blocked the sale by refusing to acknowledge the proposed buyer as a qualified Utility Trailer dealer, the suit contends.

Utility Trailer, in a response to the suit, said one of its concerns is that JX Enterprises operates truck dealerships in other areas where Utility Trailer already has trailer dealers.  

JX Enterprises has 18 locations in the upper Midwest.

Utility said it offered to help franchisee UTI liquidate its trailers, or to continue to recognize it as a dealer.

The suit seeks unspecified damages.

Representing Riddle and Peterbilt of Indiana is local law firm Stewart & Irwin, which represents a number of car dealers in the state.  

Riddle was unavailable for comment on the lawsuit.