BEIJING – Asia’s full-service airlines are hoping to win more customers by raising baggage allowances, a stark departure from the decadelong, world-wide practice of forcing passengers to travel light or face exorbitant fees.

At least four Asia-Pacific carriers, including Singapore Airlines Ltd.  -1.25% and Malaysian Airline System  -3.08% Bhd, have in recent months raised weight limits for free checked baggage on economy and premium classes by as much as 53%. The action highlights how Asia’s premium carriers are feeling the heat from fast-growing budget airlines and ultra-luxurious Middle Eastern carriers. Competition has continued to weigh on passenger yields, a key measure of airline fares.

All that added luggage weight means added cost, but it’s an expense the carriers appear willing to undertake if it gains them more passengers—and saves them from aggressive fare cuts.

“It’s not just about the cheapest seat on a flight,” said Suresh Singam, head of government and international affairs at Malaysia Airlines. “We believe there is a premium that you can charge because of the brand and value.”

Low-cost travel now accounts for a quarter of Asia’s traffic, hurting demand for full-service carriers especially in Southeast Asia, even as international passenger traffic on regional airlines remains strong, rising 5.5% in the first nine months of 2013. The fight for coach customers has become more crucial for the region’s premium airlines with the downturn in first- and business-class demand.

Illustrating the competitive landscape, around 75% of airline routes in the region are served by at least three carriers, while in Europe, some 45% of routes are served by just one or two airlines, according to the Association of Asia Pacific Airlines. The International Air Transport Association earlier cut its 2013 profit forecast for Asian-Pacific airlines by a third to $3.1 billion, representing a 23% decline from 2012, citing slowing growth in the region’s emerging markets. IATA expects only modest profit growth for the airlines next year.

“Competition keeps yields low and (profit) margins are being squeezed. Asian carriers are still finding it very tough and profitability isn’t picking up,” said Andrew Herdman, director general at the AAPA, an industry group representing 15 of the region’s full-service carriers.

Full-service airlines in the West have also endured intense competition with budget travel, causing many companies to pare back amenities to become no-frills operations themselves. In the U.S., for example, most carriers charge customers to check even one bag. In Asia, most airlines remain invested in the full-service model, though they have created budget carriers themselves to stay competitive.

“As a premium carrier, what we should do is to continue enhancing our product offerings…we won’t go the way of launching a price war,” said Austin Cheng, president of Taiwan-based full-service carrier EVA Airways Corp.  -0.31% “Our core value is to provide good service.”

Last week, Singapore Airlines said it would increase its free baggage allowance in all travel classes on most routes by 10 kilograms, matching an earlier decision by premium rival Malaysia Airlines. Coach customers will be allowed to check bags weighing as much as 30 kilograms, up from 20 kilograms previously. The decision came just as the Singapore flag carrier reported further declines in passenger yields, a trend that has continued since the fiscal year ended March 2011.

China Southern Airlines Ltd. +3.58% and Australia’s Qantas Airways Ltd.  +2.22% have also raised the allowances for coach customers on many routes.

In addition, airlines are making it easier for customers to earn frequent-flier miles on special discounted fares, while others are extending perks normally reserved for premium travelers to coach customers. For example, economy passengers transiting from long-haul flights on Garuda Indonesia GIAA.JK -2.02% will soon be able to relax at the airline’s lounges in Jakarta. Hot meals and wines remain complimentary on most full-service flights in Asia, and carriers continually upgrade coach seats and in-flight entertainment options.

Full-service airlines have significantly boosted flights within the region to better connect customers to their other regional and long-haul services. Malaysia Airlines added more flights on key regional markets and boosted its passenger traffic by 30% so far this year. The airline competes in its home turf against AirAsia, 5099.KU +1.62% the region’s biggest and most successful budget carrier, which earns around 17% of total revenues from ancillary income such as checked bags, food and early seat assignments.

Many premium Asian airlines also are relying on global alliances to extend their international reach and attract business travelers. Both EVA and Malaysia Airlines became alliance members earlier this year, and will soon be followed by Garuda Indonesia.

“We are not like Emirates which has deep pockets [and] can buy so many aircraft. We have a limited bank account,” said Emirsyah Satar, chief executive of Garuda, explaining his airline’s decision to join the SkyTeam alliance to expand its international footprint.

Mr. Satar said Asian carriers have an advantage over rapidly expanding Middle Eastern airlines because they are able to fly fast-growing routes using smaller planes that the Gulf carriers don’t have.

“We’ve got that market,” he said.

– WALL STREET JOURNAL