NEW YORK (CNN/Money) - West Coast port management and labor returned to the negotiating table early Friday morning, but despite positive comments from both sides Thursday there appears to be no imminent end to the labor dispute that has choked off U.S.-Asian trade over the last eight days.

A tugboat maneuvers through waiting freighters on the Columbia River near the Port of Vancouver in Vancouver, Wash. About 160 ships are anchored waiting to call on West Coast ports closed by a labor dispute.

The effects of the work stoppage have been spreading and some estimates now put the cost to the already troubled U.S. economy at more than $1 billion a day. Asian economies are also being affected as many exporters there essentially are shut out of their largest market. About 160 ships sit anchored waiting to call on the closed ports.

Officials of the International Longshore and Warehouse Union, which represents 10,500 members at 29 West Coast ports, and the Pacific Maritime Association, which represents major shipping lines and port terminal operators, both left federally mediated talks at about 10:30 p.m. PT Thursday describing the session as productive, a change from some of the rancorous comments earlier in the week.

"It's a good atmosphere. We have a big hill to climb," ILWU International President James Spinosa said. "We are going to continue to work. We will be back tomorrow."

Management also suggested some progress in Thursday's session.

"Tough day. Worked hard. We are going to keep at it," PMA CEO Joe Miniace said.

Friday the two sides announced an agreement that will allow ships bound for Alaska to again starting loading cargo. The two sides responded to requests by Alaska Gov. Tony Knowles and other elected officials there, who noted the short supply of food and other essential products in the state. About two-thirds of all goods sold in the state come by ship.

"We're very pleased to see both the shipping lines and the union recognize Alaska's unique dependence on shipping," said Bob King, the governor's press secretary. "Everything from the Sunday funnies to election pamphlets were affected by this lockout. There is no rail line and only one highway, and it would cost about twice as much and take considerably longer."

The equivalent of about 200,000 20-foot long containers of freight a year move to Alaska by ship, about twice as much as move by barge or truck. Oil shipments from Alaska and other nations bound for the West Coast have not been affected by port lockout, though.

Union spokesman Steve Stallone said it was too soon to say if the agreement on Alaskan freight was a sign that the two sides were getting closer to an broader agreement.

"Hopefully what we're seeing is a realization by PMA that their actions are irresponsible and there are people being unnecessarily hurt by their action," he said.

The agreement does not open up shipments to Hawaii, which depends on ocean shipments for about 90 percent of its goods and 65 percent of its food. Spokesmen for PMA and ILWU did not have a reason Hawaii was not included at this point. Many consumers there are stocking up on items from toilet paper to fresh milk due to fears of shortages.

The two sides concentrated Friday on the key issue in the labor dispute -- management demands to have shipping data downloaded into port terminal computers rather than reentered by hand by ILWU-represented clerks. Talking about technology is another sign of progress -- when the two sides held negotiations Monday, management said the union negotiators had said that the technology issue was "off the table."

Management says greater use of technology is necessary to handle the expected increases in cargo through the ports in coming years. The union says it has made proposals to give management its greater use of technology, but management said union demands for guarantees on staffing levels and jurisdiction over some work are not feasible.

PMA locked out the union Sept. 27 for 38 hours, charging that the union had coordinated a work slowdown that amounted to an attempt to have a "strike with pay." The union denies that charge. After reopening the ports Sunday morning, management charged the slowdowns continued, and reinstituted an indefinite lockout later that day. It says it won't reopen the ports unless the union agrees to a new contract or reinstitutes an expired pact that would allow arbitration of disputes over work slowdowns.

Business groups are growing eager for the ports to reopen as the effects of the work stoppage spread, and some have called for President Bush to do everything possible to reopen them. The president has the power to order the two sides back to work for an 80-day cooling off period under the seldom-used Taft-Hartley Act, but the administration has said it's committed to allowing mediation efforts to end the dispute.

The AFL-CIO Thursday called for the president not to use Taft-Hartley, although it also called for PMA to end the lockout while talks take place.

"Since both the ILWU and the PMA have agreed to federal mediation on the issue of how new technology is implemented, the PMA should end its lockout today and let the dockworkers go back to work," AFL-CIO Secretary-Treasurer Richard Trumka said. "The Bush Administration should let the two sides continue to talk and should let the bargaining process work."

But business groups are stepping up pressure on Bush to act. Among groups writing to the White House asking for action to open the ports are the Toy Industry Association (TIA), the American Association of Exporters and Importers, (AAEI), the International Mass Retail Association, which includes the nation's major retail chains, and the West Coast Waterfront Coalition (WCWC), which also represents the nation's major importers and exporters.

"We acknowledge that the negotiations between the PMA and the ILWU involve complex and sensitive issues that need to be resolved. Ideally the two parties could be left to sort out these issues themselves," the AAEI and the TIA wrote. "But their negotiations have now taken a course that seriously injures many others and involves broader interests, including your interest in pulling our country's economy out of a persistent sluggishness."

The Farm Bureau said a prolonged shutdown of West Coast ports would "inflict severe harm" on the weak farm economy, and spokesman Don Lipton said the group is preparing its own letter to the White House seeking action to open the ports.

"This has got the attention of every CEO in America," said Robin Lanier, executive director of the WCWC. "How much time can the president give mediation when he has all his friends calling him or [presidential political adviser] Karl Rove telling him there needs to be action."

The business impact of the lockout continues to spread. Thursday, New United Motor Manufacturing Inc., the West Coast's largest auto assembly plant, a joint venture of General Motors Corp. and Toyota Motors Corp., shut down operations due to lack of parts. The plant, which builds Toyota Tacoma pickups and Toyota Corollas and Pontiac Vibes for the North American market as well as a Toyota car for shipment back to Japan, is the largest importer of goods through the Port of Oakland. Other plant closings could come soon.

John Martin, president of a maritime economic consulting firm, said that he believes the impact of the loss of containerized cargo alone is already at about $1.5 billion, but it is rising rapidly due to ripple effects through the nation's freight transportation system. His estimate doesn't calculate the effect on some bulk goods such as grain, or the impact on auto imports.

"It's a continually moving target," he said. "We've tried to model this as much as we can, but things keep popping up. Rail equipment and truck equipment is getting out of balance. It's a major logistical nightmare that is now starting to affect the entire domestic supply chain, not just imports."

Some analysts believe presidential action isn't yet imminent.

"We continue to believe that the president is under some pressure not to appear anti-labor, and thus will probably not intervene until sometime next week at the earliest," Bear Stearns analyst Ed Wolfe said. "But despite his recent popularity with the Teamsters and the AFL-CIO, Bush will, in our view, most likely choose to protect the economy, which increasingly appears to be at risk the longer the port disruption continues."

ILWU members are among the best-paid blue-collar workers in the nation. PMA figures show longshoremen earned an average of $82,895 last year, while clerks earned an average of $118,844 and foremen, who are members of the union, earned an average of $157,352.

Almost 30 percent of union members in the longshoremen classification work less than 1,600 hours a year, equivalent to 40 hours a week for 40 weeks. Only a few more than half work 2,000 or more hours, which is essentially full-time employment, across the year. Those working 2,000 or more hours had average pay of $106,883 in 2001, according to PMA.  

Reuters contributed to this report