* Victory will give centre-right control of richest region
* Regional outcome has not directly link to national vote (Updates projections)
ROME, Feb 26 (Reuters) - The head of Italy's Northern League, an ally of Silvio Berlusconi, is on course to win the Lombardy regional presidency vote, giving the centre-right control of the richest and most productive area of the country.
Roberto Maroni was forecast to take 42.4 percent of the vote with the centre left's Umberto Ambrosoli on 37.2 percent, projections from RAI state television showed.
The election in Lombardy, a northern Italian powerhouse with an economy bigger than Belgium's, ended on Monday, the same day as the national election which has left Italy's political parties struggling to form a government.
The regional election result was only counted on Tuesday.
It had no direct link to the national vote but a victory for the Northern League in its home region could strengthen its alliance with Berlusconi's People of Freedom (PDL) party, which has more clout in national politics.
The two parties, which were coalition allies in Berlusconi's last government, have had a patchy relationship since their alliance broke apart when the scandal-plagued government fell in 2011 and many grassroots League members have been wary about renewing the pact.
The PDL previously ran Lombardy until a separate corruption scandal brought down regional president Roberto Formigoni last year. It agreed not to put up a candidate to run against Maroni as the price for a national election pact.
The Northern League, which has struggled to recover from a scandal of its own which brought down its founder Umberto Bossi last year, did worse than expected in the national election, winning only 18 lower house seats and 17 seats in the Senate.
It campaigned to keep a greater share of the tax revenues from Italy's rich northern industrial heartland in the regions where they are raised. Some of its members want to create a breakaway region in the north, which the party calls Padania. (Reporting by Catherine Hornby; Editing by Michael Roddy)