Philippines' largest conglomerates bid for $2.8 bln road-dike project

* Ayala, SM, Megaworld and Aboitiz join forces

* Most diversified conglomerate San Miguel to bid solo

* Nine multi-billion peso PPP deals awarded so far (Adds other bidders, background)

MANILA, Feb 27 (Reuters) - Some of the Philippines' largest conglomerates, including SM Investments Corp and San Miguel Corp, are bidding for the country's largest infrastructure scheme - a 123 billion pesos ($2.79 billion) tollway and dike project.

Four consortia filed initial documents on Friday to qualify to bid for the Laguna Lakeshore Expressway Dike project, among them Trident Infrastructure and Development Corp - a partnership of Aboitiz Equity Ventures Inc, Megaworld Corp , Ayala Land Inc and SM Prime Holdings Inc .

Trident marks the first time those four groups have joined forces for a single venture. (http://bit.ly/1DY7I20)

San Miguel and two other consortia - Rainbow Holdings Inc and the MTD-PAVI-Hanshin Consortium that includes Malaysia's MTD Capital Berhad - also submitted pre-qualification documents.

More than 20 local and foreign companies including JG Summit Holdings Inc and France's Egis Projects SA earlier obtained necessary documents to bid for the government's largest public-private partnership (PPP) project to date.

The project includes the construction of a 47 kilometre (29.2 mile) expressway and a 45 kilometre flood control dike, involving the reclamation of around 700 hectares (1,729.74 acres) of land south of the capital Manila.

The government, which aims to upgrade infrastructure and boost economic growth, has awarded nine projects worth 130 billion pesos since launching the PPP programme in 2010.

President Benigno Aquino earlier this month approved the roll out of an additional $5.7 billion worth of road and railway projects through the PPP scheme. ($1 = 44.07 Philippine pesos) (Reporting by Neil Jerome Morales)