German luxury carmaker Daimler AG won't slash its workforce to close the gap with rivals BMW and Audi in terms of profitability, the company's personnel chief said.

I see no reason to look exclusively at personnel when it comes to increasing efficiency, Wilfried Porth told Reuters in an interview, adding staff costs account for less than a fifth of group expenses.

Daimler's Mercedes, which had a 9 percent operating margin in 2011, has been lagging Audi and BMW in terms of profitability, even though the two tend to sell cars priced below those of Mercedes.

BMW and Audi have yet to report full-year 2011 results.

Daimler had 271,000 employees around the world last year, of whom almost 168,000 were based in Germany, and Daimler plans to further increase that number this year.

In 2012 we currently expect a positive development, Porth said, though he added staff numbers will growth more slowly this year than in 2011, when the company hired 14,000 new workers.

(Writing by Maria Sheahan)