Energizer (NYSE:ENR) may have reported some pretty sharp quarterly numbers today, but investors registered worry. Several variables pointed to a slowdown for Energizer, including the idea that the company's going to have to shell out some cash to fend off archrival Gillette (NYSE:G).

Second-quarter earnings at Energizer rose 62% to $53.4 million, or $0.63 per share. However, Energizer's earnings included unrecognized tax benefits of $0.11 per share and income from intellectual property rights of $0.01 per share, without which earnings would have been $0.51 per share. Earnings also got a lift from a $0.12 per-share benefit from the Schick purchase, which included $0.04 per share related to foreign currency.

Energizer's sales increased 64% to $592.9 million. However, the battery side of things -- where Energizer competes with Gillette's Duracell and Rayovac (NYSE:ROV) -- showed signs of weakness here in North America, with a 3% drop in sales. International revenues, on the other hand, increased 13% on favorable currency as well as higher volumes in Asia.

If investors soured on Energizer today, there were several reasons why the earnings outlook is a bit depressed going forward. While the foreign currency climate will remain "favorable," it will be so at a "substantially lower level" than in the first half of the year. Year-over-year tax comparisons are expected to be unfavorable for the remainder of the year.

Meanwhile, Energizer's now-infamous razors-and-blades business is about to face tough comparisons to last year's launch of new products, which boosted sales. Energizer also said it plans "significant advertising and promotion" in the third quarter, which translates into dropping cash to ward off the competition.

It's not too surprising, given the competitive landscape. In the dog-eat-dog world of batteries and blades, back in January, we got word that Gillette had booked a whopping 28% increase in ad spending to boost market share. The move bore fruit in pushing forward its Mach3 product, which competes with Energizer's Schick Quattro.

So, despite Energizer's having beat analysts' expectations today, the forward view is cloudy. Investors reflected that view; the stock was down 6% in recent trading. With the head-to-head rivalry between Gillette and Energizer, particularly in the lucrative razor blade arena, it's tough to call a winner and possibly a good time to wait on the sidelines.

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Alyce Lomax does not own shares of any of the companies mentioned.