(Reuters) - The Obama administration is expected on Thursday to announce up to $527 million in grants for transportation projects nationwide.

The oversubscribed Tiger program awards money to states and local governments for road, bridge, rail, port and other priority infrastructure projects.

Transportation Department officials said last month there were 820 applications for $527 million in available grant funding.

Congress has been struggling to approve a long-term transportation funding bill, heightening interest outside of Washington for any additional sources of federal money.

The administration has proposed $2 billion in Tiger funding for 2012, but the fate of the initiative is unclear with deficits high and all federal spending under closer scrutiny in Congress.

The Transportation Department funded more than 90 projects worth more than $2.1 billion in the first two years of the Tiger program.

(Reporting By John Crawley; Editing by Andrew Hay)