XEGE-AM received its first concession on October 29, 1953. It was owned by Radio Comercial de Baja California, S.A. de C.V., which was owned by Jesus Eguia Molleda, and broadcast as a daytimer on 1150 kHz. By 1969, the callsign had changed to the current XERM-AM to match the sale of Radio Comercial de Baja California to Nicolas Rodriguez Merida. In 1999, XERM was sold to Radio Formula.
XEYC received its first concession on February 25, 1949. It operated on 1460 kHz with 1.000 watts and was owned by and named for Ysela Fernandez Caballero de Yañez. The station was known as "Radio Ysela". Fernandez Caballero died on June 21, 1972. XEYC was sold to XEYC, S.A., in 1980. In 1998, the concession was sold directly to Formula in the person of Rogerio Azcarraga Madero. The 1999 concession listed XEYC on 1030 kHz with 5.000 watts day and 500 watts night. The 2009 concession lists 1460 kHz as the frequency, but promotional materials mentioned 1030 AM until XEYC returned to 1460 on ...
XHERW-FM is a radio station on 101.1 FM in Leon, Guanajuato. It is owned by Radio Formula and carries its news and talk format in conjunction with XHACN-FM 107.1.
XEXK-AM 1080 received its concession on January 20, 1972. It was owned by Radio Poza Rica, S.A. and operated as a 250-watt daytimer. In 1978, 1986 and 1987, technical changes were approved boosting the station to 500 watts in 1978, adding a 100-watt nighttime service in 1986 and increasing that to 250 watts in 1987. It further boosted power to 10.000 watts in 1994 and was sold to Radio Formula in 2000. XEXK was authorized to move to FM in November 2010 and soon after moved to its own transmitter site, separate from Radiorama Poza Rica.
XHYF-FM is a radio station in Hermosillo, Sonora. Broadcasting on 91.5 FM, XHYF is owned by Radio Formula and operated by the Expreso newspaper pursuant to a local operating agreement.