The United Parcel Service strike may be settled, but the after-effects linger on in Los Angeles.

Last week, UPS phone lines were tied up with callers apparently trying to track their packages after a huge surge in orders in the days following the strike settlement.

When callers to the Los Angeles district office did get through, some were greeted with a message that the company could not pick up packages because it already had as many pickups as it could handle.

“We are unable to pick up your package,” the message said. “All of our staff is busy. To get a list of places to take your package to, please press ‘2.’ ”

Steve Chisum, a UPS spokesman for eastern Los Angeles County and the Inland Empire, said the nation’s dominant package shipper was trying to process all of the tracking calls that came in from people whose deliveries had not arrived at their destinations.

“We had 16 million packages a day to ship during the first week after the strike and an average of 15 million the next week. Our pre-strike norm was 12 million,” Chisum said. “Many of these packages were supposed to take about a week to get to their destination. So this is the week that people have been calling to check on their packages. Our phone system has been quite busy.”

Chisum said the higher-than-normal number of packages has taxed UPS’s delivery system, leading to a slightly longer-than-normal average delivery time. That has been compounded by the decision of many UPS part-time workers not to return to the company after the strike, forcing managers to man the phone lines.

The situation was complicated last week by phone equipment problems unrelated to the strike, Chisum said.

Meanwhile, L.A.-area companies have returned to UPS, but with a twist: Some companies are reducing the share of packages they send via UPS.

“Before the strike, we shipped 90 percent of our garments through UPS. Now, we are trying for 75 percent,” said Vera Campbell, owner of Knit Works, a Los Angeles maker of junior sportswear. “Once you realize you’re in bed with someone as much as we were with UPS, you try to make sure you won’t be caught off guard again.”

Campbell said the remaining 25 percent of Knit Works’ clothing is shipped through a company called RFS Inc. and through the U.S. Postal Service.

At Blue Cross Beauty Products in Pacoima, President Mark Friedman said the company would continue to ship 100 percent with UPS.

“It’s a matter of time and convenience. The U.S. Post Office does not pick up, the rates are higher and you can’t instantaneously track the packages,” Friedman said.

Yet Friedman said he has experienced some of the delivery problems plaguing UPS. “We have been trying to track a package that did not arrive today as it was supposed to. So far, there is no word,” he said.

Despite the difficulties, UPS’s volume last week averaged 11.8 million packages a day, just 1.7 percent less than the pre-strike average of 12 million, Chisum said.

“By next week, we expect our numbers to stabilize at somewhere around 5 percent less than our pre-strike levels. We expect all of our customers to return, but many will have also turned to secondary carriers just for insurance.”

After the volume stabilizes, Chisum said the company will decide on how many layoffs will be made to readjust to the anticipated lower volume.

UPS’s loss is shaping up as gains for its competitors. At Federal Express’ Hollywood station, for example, station operations manager Deborah Hand said volume is up “substantially” over pre-strike levels.

“A lot of people are still a little sore from the strike. They are at least willing to look at us now, whereas before the strike, they only went with UPS,” Hand said.

One week after the UPS strike ended, Federal Express lifted its 10-package-per-customer limit imposed during the strike, she said.