Both the Mercury News and Chronicle reported circulation increases on Sundays but declines in daily circulation for the past six months, according to the Audit Bureau of Circulations (ABC).

Last year, the Merc added the Contra Costa Times, Oakland Tribune, San Mateo County Times and other papers to its circulation total. This year the Merc added the Marin Independent Journal, Santa Cruz Sentinel, Vallejo Times-Herald and Vacaville Reporter to its circulation. All of the papers are controlled by MediaNews Group of Denver. The moves helped the Merc become the fifth largest newspaper in the country in terms of circulation, with 577,665 copies daily and 636,999 on Sunday, according to yesterday’s report.

Circulation of the Mercury News was down 2.9% daily and up 0.7% Sunday compared to a year ago.

The San Francisco Chronicle saw a 2.5% decline in daily circulation to 235,350, and a 2.2% increase in Sunday circulation to 292,459.

ABC is now using a new metric for newspapers, by combining their print circulation with online pageviews. In that competition, the Merc’s audience is 2.6 million and the Chron came in at slightly under 2 million.