Over 11,000 H-1B visa slots, once the most sought-after among Indian professionals, are still vacant against the Congress-mandated cap of 65,000 for the fiscal 2010, according to US immigration authorities.

"As of October 30, approximately 53,800 H-1B cap-subject petitions had been filed," the US Citizenship and Immigration Services said.

This is against the Congressionally-mandated cap of 65,000 H-1B visas for this year.

This is for the first time in several years that thousands of H-1B visas are still to be filled up. In previous years, the entire visa slots used to be grabbed on day one.

Many a times, the USCIS had to resort to a computerised lottery to determine the successful candidates.

The USCIS also announced that it has approved sufficient H1-B petitions for aliens with advanced degrees to meet the exemption of 20,000 from the fiscal year 2010 cap.

"Any H1-B petitions filed on behalf of an alien with an advanced degree will now count toward the general H1-B cap of 65,000," it said.

"USCIS will continue to accept both cap-subject petitions and advanced degree petitions until a sufficient number of H-1B petitions have been received to reach the statutory limits, taking into account the fact that some of these petitions may be denied, revoked, or withdrawn," it said.