Factbox: Inside the two biggest sovereign rating agencies

(Reuters) - Two credit rating agencies hold the key to the global economy in their hands as they contemplate a downgrade of the U.S. sovereign rating.

The following are some facts about the two companies -- Standard & Poor's and Moody's Investors Service -- and their methods for determining sovereign credit ratings: S&P

Headquartered in London, S&P employs 1,019 credit analysts with 223 supervisors. It has more than a million ratings outstanding on municipal government and sovereign entities, according to a report this year by the U.S. Securities & Exchange Commission.

S&P employs 6,100 people worldwide and is owned by the U.S.-based firm McGraw Hill.

David T. Beers leads S&P's 80-person sovereign team. Senior Director David Gill and Frankfurt-based Managing Director Moritz Kraemer are also major players on that team.

S&P'S SOVEREIGN RATING PROCEDURE

Sovereign analysts follow a general procedural profile when determining a country's rating and report to a central committee. John Chambers, the chairman of S&P's sovereign rating committee, and his boss David Beers, the global head of sovereign ratings, attend the S&P meetings on U.S. ratings.

The primary analyst for each country -- Nikola Swann for the United States -- with the help of support analysts, distributes a draft report on the country to members of the sovereign ratings committee, which then meets to discuss the report and the country's rating.

The committee debates points in the ratings recommendation and then votes on a final rating. Each committee member has to explain his or her vote. Members can include analysts who rate subsectors of the country, such as banks, companies, municipal bonds and sovereign analysts for other countries, ensuring that peer analysis is a core part of the process.

The decision is kept confidential until the issuer is informed. The issuer has the opportunity to appeal. The committee is comprised of S&P analysts and is based on a majority vote.

MOODY'S INVESTOR SERVICE

Moody's Corp, listed in New York, is the parent of Moody's ratings agency. The company has its headquarters in New York and employs around 4,500 people worldwide. According to the SEC report, Moody's has 1,096 credit analysts with 143 supervisors.

Its sovereign team is led by Bart Oosterveld, who is also chief credit officer for public sector ratings, which includes sovereign ratings. There are about 40 people on the Moody's sovereign team.

Moody's has more than 860,000 outstanding ratings on municipal government and sovereign entities.

HOW MOODY'S RATES SOVEREIGNS

Moody's also clears its sovereign ratings through a committee after they are first formulated by analysts. According to its website, Moody's maintains an "active dialogue" with the entities it rates.

A former Moody's employee said the firm's sovereign analysts generally have PhD's and are often fluent in the primary language of the country they cover.

Moody's can have up to 20 people on its committee. The U.S. analyst is Steven Hess.