Pimco, the world’s biggest bond-fund manager, on Tuesday extended maturity limits on two of its actively managed fixed-income ETFs, the Pimco Government Limited Maturity Strategy Fund (NYSEArca: GOVY) and the Pimco Prime Limited Maturity Strategy Fund (NYSEArca: PPRM).

The Newport Beach-Calif.-based firm filed with the Securities and Exchange Commission to allow GOVY to buy short-dated securities with ratings ranging from “Aa” to “Aaa” that mature up to three years from date of purchase, compared with two years previously.

For PPRM, Pimco can now buy “A”- to “Aaa”-rated dollar-denominated securities that mature up to 18 months from the purchase date, compared with 397 days previously. It left unchanged the two-year limit on floating-rate U.S. government agency securities the fund can buy.

Three-year U.S. Treasury notes now yield 1.32 percent, while two-year notes are yielding 0.80 percent, according to data compiled by Bloomberg. AA-rated one-year corporate debt is currently yielding 0.80 percent.

Pimco will now also allow the Prime Limited Maturity Strategy ETF to invest in variable-rate securities with maturities of more than 18 months “if the interest rate will be adjusted,” according to the filing. It said the fund could demand payment of principal from the issuer within that period.