Newport Beach-based Pacific Investment Management Co. has received a U.S. patent for the methodology behind its global bond index.

The patent was granted by the U.S. Patent and Trademark Office to Pimco founder and Co-Chief Investment Officer Bill Gross and Ramin Toloui, co-head of the firm’s emerging-markets portfolio. Toloui has been leading Pimco’s Singapore office since the beginning of this year, overseeing the firm’s Asia-Pacific operations.

Pimco’s Global Advantage Bond Index, first launched in 2009, is designed to assess a country by the size of its economy through its gross domestic product rather than the total market capitalization of a bond issuer’s outstanding debt.

Pimco has launched other indexes based on similar GDP-weighting methods, including the European Advantage Government Bond Index, which was introduced in 2010.

“Rising debt levels in industrial countries raise fundamental questions about the construction methodology of traditional bond indexes, [which are] market-capitalization weighted,” Toloui wrote in 2010 for a fall issue of Journal of Indexes. “GDP-weighting does not reward countries with high levels of debt issuance. Countries with higher debt-to-GDP levels generally have a lower representation in a GDP-weighted index.”

Pimco’s new income-focused index will reflect current trends and ongoing changes in global bond markets, “a ‘new normal’ environment where economic and financial power is shifting from developed to emerging markets,” Toloui said in a recent statement.