LONDON — An economic slowdown in South Asia, coupled with difficult market conditions in West Africa, have prompted Unilever P.L.C. to project 2019 full-year underlying sales to fall shy of the company's guidance range. Earnings, margin and cash are not expected to be affected, the company said.

“We have previously guided to being within the lower half of our multiyear 3% to 5% range, so in the 3% to 4% space,” Alan W. Jope, chief executive officer, said during a Dec. 17 conference call with analysts. “And we do now expect to be slightly below this.”

Mr. Jope identified three main reasons for the miss. First, the markets in South Asia have slowed.

“We define South Asia as India, Pakistan, Bangladesh, Sri Lanka and Nepal,” Mr. Jope said. “As you know, that group is where we have one of our biggest and most successful businesses. It’s been a strong driver of growth. And the market there has now slipped to below 5% growth. That compares to market growth rates that were above 10% just a year ago. So we’ve seen quite a strong deceleration through 2019. And there’s an extra point of data. We’ve seen that the slowdown is particularly coming in rural India, which for the first time in a while is now growing at a slower rate than urban India. So that’s the first major driver.”

The second driver is a market slowdown and liquidity squeeze in West Africa, specifically in Nigeria and Ghana.

“Consumer demand is down, but liquidity crunches are disrupting our distributor buying patterns, and we’ve seen inventory come out of the system there in West Africa,” Mr. Jope said. “… the tough economic and political factors there are likely to continue for a while, and so the business has taken bold action to reset trade inventory levels.”

The third reason for the expected miss in 2019 involves challenges in developed markets, Mr. Jope said.

“So in North America, we had previously called out some competitive hotspots,” he said. “And actually, this is a particularly frustrating thing to be sharing because we’re seeing significant positive indicators of success on addressing those competitive hotspots. For example, our dressings and our ice cream business are now growing market share on a 12-week basis. North American hair care is now gaining share on a 4-week basis. That’s a little shorter time period than we normally look at, but I wanted to give you a sense that the competitiveness issues in North America are coming back. However, it will take more time to get North America growing as we would like. And I think as everyone is aware, trading conditions in Europe are not getting any easier.”