MOBILE, Ala. (AP) — An agreement between union longshoremen and shipping companies on the key contract issue of royalty payments should avoid a strike that could have hurt Alabama's automotive industry, the head of the state port said Friday.

While issues remain to be negotiated on a dock workers' contract covering the East Coast and Gulf Coast, Lyons said they're "not that big" compared with previous topics. The national union agreed Friday to extend its contract for 30 days.

"I don't see anything that would prevent ... an agreement over the next 30 days," Lyons said.

An Alabama-based leader of the International Longshoremen's Association wasn't as optimistic.

"It is too early for people to be saying that the chance for a strike is over. We still have a ton of issues to bargain over nationally, and there is local bargaining for some that has to be achieved," said Mark Bass, president of Local 1410 in Mobile.

The union has about 800 members in Mobile, Bass said. Lyons estimated union membership in Mobile at around 400 of the roughly 3,000 people whose jobs are tied directly to the port.

The extension agreement Friday averted a possible strike that could have begun Sunday, after the union and an alliance of port operators and shipping lines resolved a main issue involving royalty payments to longshoremen for each container they unload.

Lyons said a longshoremen's walkout would affect container shipments through Mobile, which handles about 2 million tons of such imports and exports annually.

While container shipments represent less than 10 percentage of the total tonnage that moves through the port each year, Lyons said the cargo shipped in the big, steel boxes includes important quantities of auto parts, manufacturing items and chemicals.

The docks rely on union members to move the containers on and off ships, and a walkout would cause problems far north of Mobile, Lyons said.

"Hyundai Manufacturing would have a tough time," Lyons said. "We do roughly 400 containers for them a week, so it would have affected them."

The union has five locals in Mobile, and workers had begun preparing for a strike before the extension, said Bass. He said a strike could have a ripple effect through the state.

"It would be a pretty big deal to have Hyundai, Mercedes, other auto companies, the paper industry, have an impact with this," he said.

Bass, a member of one of the union's national negotiating teams, said he hoped the sides can avoid a strike, but he isn't certain.

"There is still some important talking to be done," Bass said.

Lyons said a strike wouldn't hurt Mobile as badly as East Coast ports because the percentage of union members is far less in Alabama than other places.