ALOR SETAR, Malaysia, July 30 (Reuters) - Malaysia is aiming for investment of US$51.2 billion in mostly private funding over 18 years to turn its mainly agricultural north into a logistics, food-processing and tourism powerhouse by 2025.

The measures are part of the prime minister's gameplan to bolster support in the country's ethnic Malay heartland as expectations grow that his government plans to call snap general elections, perhaps as soon as early next year.

"The government is finalising various incentive packages and they will be announced soon," Abdullah Ahmad Badawi told a gathering of several thousand people to launch the programme in the northern town of Alor Setar, 430 km (270 miles) from the capital.

"Several programmes that have been identified in the initial phase are estimated to involve additional costs of five billion ringgit," he said, referring to costs in addition to an existing state development plan, the Ninth Malaysia Plan.

Dubbed the Northern Corridor Economic Region, the zone marks Abdullah's growing penchant for mega projects once the hallmark of his predecessor-turned-rival Mahathir Mohamad.

The northern corridor plan follows the Iskandar economic region in the country's south, bordering Singapore. Abdullah is also pouring money into building Southeast Asia's longest bridge as well as big-ticket items like roads, railways and airports.

Other projects being planned include oil refineries and a mammoth oil pipeline.

Except for the island of Penang, the 4.3 million people in the region are mostly Malays, the backbone of Abdullah's ruling party, the United Malays National Organisation (UMNO).

Two-thirds of them are in the region's rice-growing areas. The average annual income of around 2,477 Malaysian ringgit ($717) per household, is the lowest among the six regions in the country except for the east coast.

"At the moment, they are down below and also they will not be happy where they are," said Nur Jazlan Mohamed, an UMNO lawmaker. "They have been neglected for a long time."

Under the Northern Corridor plan, the government will provide about a third of the 177 billion ringgit, or $51.2 billion, investment required over the period from 2007 to 2025, with the rest coming mainly from private investors, Abdullah added.

"This will breathe new life into the region's development," Abdullah said.

The blueprint, prepared by conglomerate Sime Darby , targets Malaysia's four northern states of Penang, Perak, Perlis and Kedah, and aims to boost their GDP to 214 billion ringgit in 2025, from 52.7 billion in 2005.

It will create 500,000 jobs by 2012, doubling to a million by 2018.

Kedah and Perlis are the ricebowl of Malaysia, contributing the bulk of the country's annual production of rice, while the northern island of Penang is a key centre for electronics manufacturing.

Infrastructure projects will include the construction of a 24-km (15-mile), 3.0 ringgit billion bridge and a 1.1 billion ringgit monorail in Penang. Others include improving and expanding Penang airport and seaport.

Besides rice-farming, the region sees little other economic activity -- fewer than a third of the tourists to Malaysia visit the area and just about 20 per cent of the manufacturing investments in Malaysia are in this northern belt.

Farmers hailed the plan, saying it would help raise their monthly income by as much as three times through better seeds.

"But this will also ensure UMNO's dominance in this state," said a 71-year-old farmer, Rahim Yaacob.

One commentator said Abdullah, in power since 2003, was showing his political clout ahead of the polls.

"From modern agricultural practices involving harvesting padi three times a year to the construction of Penang's second bridge, the projects are expected to fire up voters in these four states," columnist Wong Chun Wai wrote in the Star recently.