– For the second time in seven months, Toyota and Ford both claim to produce the world’s top-selling car. The clash shows how counting in the global automotive industry is complicated.

Ford said Tuesday that its Focus compact car was the leading global nameplate, with 1.02 million sales last year, citing R.L. Polk & Co. data that pegged Toyota’s Corolla deliveries at 872,774. Toyota replied with a statement late Tuesday that said it sold 1.16 million Corollas.

Determining which company is correct isn’t clear-cut. The dispute followed a similar spat in August, when Ford claimed a six-month global sales lead for Focus and cited IHS Automotive data that excluded some derivatives of the Corolla such as Matrix in the U.S., the Auris in Europe and the Verso in Japan. Analysts also calculate global sales differently on the basis of autos sold by joint-venture partners.

“There’s no simple answer here — it’s basically for bragging rights, so you define it however you like to suit your purposes,” Alan Baum, principal of Baum & Associates, an auto consulting firm in West Bloomfield, Mich., said by telephone. “Suffice it to say these are both global models that are extremely popular and whose sales are likely to grow as the volumes in developing countries increase.”

Erich Merkle, Ford’s U.S. sales analyst, reiterated late Tuesday that Focus was the “bestselling nameplate.” The 1.02 million figure “is a pure number that is verified by a third party,” Merkle said in an e-mail.

Polk is unable to provide data on global sales by nameplate beyond what Ford has released, said Michelle Culver, a Polk spokeswoman who works for Lambert, Edwards & Associates.

“Toyota sold 1.16 million Corolla nameplate vehicles globally in 2012,” Mike Michels, the carmaker’s U.S. vice president of communications, said late Tuesday in an e-mailed statement. “Corolla registrations attributed to Polk come up short by nearly 300,000 units. This discrepancy is glaring and we have requested clarification.”