Overland Park ? Shares of transportation companies Yellow Roadway Corp. and USF Corp., which plan to merge later this year, dropped further Friday after the USF said its first quarter earnings would miss Wall Street expectations.

Chicago-based USF, which is to be acquired by Yellow in a deal worth $1.37 billion in stock and cash, said Thursday it expected first quarter earnings in the range of 12 to 16 cents per share.

Analysts surveyed by Thomson First Call expected 38 cents per share; the company reported earnings of 32 cents per share during the same quarter a year ago.

USF shares dropped 47 cents, or about 1 percent, Thursday on the Nasdaq Stock Market and declined another $2.83, or 5.8 percent, to $45.67 on Friday.

Yellow shares dropped $1.29, or 2.1 percent, Thursday on the Nasdaq and slid an additional $4.69, or almost 8 percent, to $54.45 Friday.

USF blamed its soft showing on slow business from the auto industry, sluggish growth in the northeast and stiff competition in the southeast. It also predicted “high single-digit” growth in quarterly revenues and “mid single-digit” growth in quarterly tonnage.

Bill Zollars, chief executive at Overland Park-based Yellow, said Friday the merger could still provide value once the two companies teamed up and slashed costs, which are expected to eventually reach $150 million.

“Given their first quarter revenue growth and tonnage increase, we believe the business fundamentals remain sound,” Zollars said in a statement.

Bear Stearns trucking analyst Ed Wolfe said he expected Yellow to complete the acquisition because walking away would open USF to acquisition by competitors. However, he also said he was lowering his earnings predictions for Yellow post-merger from $5.28 to $4.91 per share in 2005 and from $6.48 to $6.12 per share in 2006.

“We continue to believe that YELL’s acquisition of USFC offers great potential upside reward and that (earnings) estimates will ultimately begin to climb again into the mergers completion,” he said in a research note.