(Reuters) - The Supreme Court rejected on Monday a request to speed up a ruling on President Barack Obama's healthcare overhaul, his signature domestic achievement that has provoked a fierce political and legal battle.

The justices turned down the state of Virginia's request to invoke a rarely used procedure to bypass the normal appeals process and speed up a Supreme Court ruling on the law's constitutionality.

The justices' widely expected decision to allow the sweeping law to be considered first by an appeals court under the regular process probably puts off any Supreme Court review until its 2011-12 term that begins in October.

Legal and financial analysts said a top court ruling could come before the 2012 U.S. elections, in which the politically charged law could face renewed criticism from Republicans and could emerge as a major issue as Obama seeks re-election.

Several federal trial judges around the nation have upheld the law but others have declared it unconstitutional on the grounds Congress overstepped its authority in requiring that Americans start buying health insurance in 2014 or pay a penalty.

Those rulings have been appealed with arguments set in May before a U.S. appeals court based in Virginia, in early June before appeals courts in Cincinnati and Atlanta and in September in Washington, D.C.

After the appeals courts have ruled, the legal battle is expected to return to the Supreme Court.

(Editing by Jackie Frank)